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RARY 


TABLES 


FOR  THE 


Determination  of  Common  Minerals 

CHIEFLY  BY  THEIR 

PHYSICAL  PROPERTIES 

WITH  CONFIRMATORY  CHEMICAL  TESTS 
BY 

W.    O.    CROSBY 

1 1 

ASSISTANT  PROFESSOR  OF  STRUCTURAL  AND  ECONOMIC  GEOLOGY  IN  THE 
MASSACHUSETTS  INSTITUTE  OF  TECHNOLOGY 


THIRD     EDITION 

REWRITTEN  AND  ENLARGED 


BOSTON 

PUBLISHED  BY  THE  AUTHOR 
1899 


s      ?>  I 

V 

EARTH 

SCIENCES 

LIBRARY 


Copyright,  1895, 
By  W.  O.  CROSBY. 


PRINTED  BY  J.  ALLEN  CROSBY, 
JAMAICA  PLAIN,  MASS. 


PREFACE. 


The  primary  objects  of  any  system  of  determinative  mineralogy 
should  be:  (i)  to  enable  the  student  to  identify  certainly  and  easily 
such  minerals  as  he  is  likely  to  meet ;  and  (2)  to  cultivate  his  powers 
of  observation  and  discrimination,  and  increase  his  familiarity  with 
the  various  species  and  natural  groups  of  minerals.  The  first  of 
these  primary  objects  has  been,  rightly  enough,  the  chief  aim  of 
previous  tables  ;  but  it  is  to  be  hoped  that,  as  regards  its  direct  edu- 
cational value,  determinative  mineralogy  will  not  always  be,  as  it  is 
now,  far  behind  determinative  or  analytical  botany. 

The  principal  defects  of  the  best  tables  now  in  use,  so  far,  at  least, 
as  the  general  student  is  concerned,  are  that  they  have  too  wide  a 
scope,  embracing  all  or  a  very  large  proportion  of  the  known  species 
of  minerals,  and  that  the  determinations  depend  almost  entirely  upon 
the  chemical  behavior  of  the  species. 

It  is  scarcely  possible  to  overstate  the  enormous  disparity,  as  regards 
their  abundance,  between  the  two  or  three  hundred  common  minerals 
and  the  one  thousand  or  more  rare  species.  The  former  are  found 
abundantly  in  many  localities,  and  in  all  good  collections,  and  are, 
generally  speaking,  the  only  species  the  student  will  meet  or  have 
occasion  to  identify  ;  while  the  latter  are  very  restricted  in  distribution, 
being  often  known  from  only  a  single  locality,  occurring  for  the  most 
part  in  impure  or  very  minute  specimens,  and  being  inadequately 
represented  even  in  the  largest  and  most  complete  collections. 

The  advantages  of  limiting  determinative  tables  to  the  common 
species  are  that  they  are  then  far  less  voluminous  and  complicated, 
the  determinations  can  be  made  more  readily  and  accurately,  and 
the  use  of  difficult  or  uncertain  tests  is  avoided.  The  only  disadvan- 
tage is  that  there  must  often  remain  the  possibility  that  the  specimen 
in  hand  belongs  to  one  of  the  rare  species  not  included  in  the  tables. 
But,  as  already  explained,  this  difficulty  is  very  small ;  and  it  cannot 
be  entirely  obviated  by  the  use  of  the  most  perfect  tables,  since  it  is 
probable  that  a  large  proportion,  perhaps  a  majority,  of  the  rare 
species  are  still  unknown  and  unnamed. 

Chemical  or  blowpipe  tests  are  valuable,  since  the  indications  which 
they  afford  are  usually  very  definite  and  precise;  and  since  they  direct 
the  student's  attention  particularly  to  the  chemical  composition  and 
behavior  of  the  species  he  is  investigating,  which  is  of  great  im- 
portance. Nevertheless,  there  are  several  good  reasons  why  they 


M255839 


should  occupy  a  subordinate  place  in  a  system  of  determinative  min- 
eralogy intended  for  general  use.  Not  the  least  of  these  is  their 
inconvenience,  since  they  require,  in  the  aggregate,  a  considerable 
amount  of  apparatus  and  re-agents,  in  other  words,  a  blowpipe 
laboratory.  This  consideration,  and  the  knowledge  of  chemistry 
which  the  system  demands,  practically  restrict  the  instruction  to  high 
schools  and  colleges ;  and  even  then  the  chemical  system  is  not  found 
to  be  practicable  in  after  life,  when  the  student  of  mineralogy  no 
longer  has  access  to  the  facilities  afforded  by  the  school.  Every 
teacher  of  blowpipe  analysis  must  have  noted  and  lamented  the  fact 
that,  as  a  rule,  the  elaborate  system  so  carefully  taught  is  used,  after 
the  students  leave  school,  only  by  the  few  who  become  professional 
mineralogists,  chemists  or  mining  engineers. 

Perhaps  the  most  serious  objection  to  the  chemical  tables  is  that 
their  use  has  comparatively  little  tendency  to  render  their  aid  unneces- 
sary, by  making  the  student  more  familiar  with  the  external  appear- 
ances of  minerals.  Unquestionably,  determinative  tables  are,  at  the 
best,  a  necessary  evil.  It  were  far  better  to  recognize  minerals  on 
sight,  by  their  structural  and  physical  characters ;  and,  other  things 
being  equal,  the  preference  should  be  given  to  that  system  of  deter- 
mination which  promises  the  largest  development  of  this  power  in  the 
student. 

These  Tables  are,  then,  an  attempt  to  determine  about  two  hun- 
dred minerals  chiefly  by  their  more  obvious  physical  and  structural 
features,  with  confirmatory  chemical  tests.  The  latter  will  not 
usually  be  required  when  the  specimens  are  pure  and  well  charac- 
terized. But  they  are,  as  a  rule,  so  simple  and  decisive  that  their 
use  is  strongly  recommended  whenever  convenient  and  the  deter- 
mination is  not  otherwise  perfectly  satisfactory.  Only  those  tests 
have  been  selected  requiring  the  minimum  of  apparatus,  re-agents 
and  previous  chemical  training,  with  a  view  to  adapting  the  Tables 
to  the  use  of  common  schools  and  private  students. 

The  various  properties  of  minerals,  and  all  the  chemical  and  blow- 
pipe tests  referred  to  in  the  Tables,  are  fully  explained  in  the  intro- 
duction. 

The  chief  distinctive  feature  of  this  edition  of  the  Tables  is  the 
placing  of  the  important  properties  of  streak,  hardness,  and  specific 
gravity  on  a  more  satisfactory  and  definite  basis  by  suitable  pro- 
vision for  their  more  ready  and  accurate  determination,  and  the 
addition  of  the  Supplementary  Tables,  embracing  one  hundred  of 
the  less  common  minerals.  This,  together  with  twenty-five  other 
species  added  to  the  regular  Tables,  reduces  almost  to  zero  the 
probability  that  an  unknown  mineral  is  one  not  embraced  in 
the  scope  of  this  work.  Following  the  Supplementary  Tables  is  a 
synopsis  of  the  classification  of  minerals  ;  so  that,  although  this  little 
work  is  not  in  any  sense  a  manual  of  mineralogy,  constant  reference 
to  the  more  comprehensive  treatises  is  avoided. 

Massachusetts  Institute  of  Technology, 
Boston,  Jan.  15,  1895. 


INTRODUCTION. 


The  properties  or  natural  characteristics  of  minerals,  by  which  they 
are  known  and  recognized,  may  be  arranged  in  three  classes,  as 
follows  :  — 

1 .  Properties  relating  to  the  form  and  structure  (crystallization,  etc.) 
of  minerals  —  morphologic  properties. 

2.  Properties  relating  to  the    action  on  minerals  of   the  various 
physical  forces  — physical  properties. 

3.  Properties  relating  to  the  composition  and  chemical  behavior  of 
minerals  —  chemical  properties. 

For  the  sake  of  convenience,  and  to  indicate  their  subordinate 
position  in  these  Tables,  the  chemical  properties  are  described  last, 
although  in  a  systematic  treatise  on  mineralogy  this  class  would 
properly  come  first. 


MORPHOLOGIC  PROPERTIES    OR    CRYSTALLOG- 
RAPHY. 

The  principal  forms  and  structures  of  minerals  are  those  due  to  their 
crystallization ;  but  there  are  other  kinds  that  are  quite  independent 
of  crystallization.  Hence  crystallography  is  only  a  part,  although  the 
main  part,  of  the  general  science  of  the  forms  and  structures  or 
morphology  of  minerals. 

Definition  of  a  Crystal. — A  crystal  is  a  natural  solid  bounded  by  plane 
surfaces  symmetrically  arranged  with  reference  to  certain  imaginary 
lines  or  directions  of  growth  passing  through  its  centre  and  called  the 
axes.  Most  crystals  break  or  cleave  with  great  ease  in  certain  defi- 
nite directions  ;  and  this  geometric  splitting,  or  crystalline  cleavage,  as 
well  as  certain  optical  properties  of  crystals,  proves  that  crystallization 
means  regularity  of  internal  structure  as  well  as  of  external  form. 

Degrees  of  Individualization  of  Crystals. —  Crystals  are  the  mineral 
individuals,  and  several  degrees  of  distinctness  and  perfection  of 
crystallization  or  individualization  are  recognized,  as  follows  :  When 
the  crystals  are  distinct  or  separate  and  so  nearly  perfect  that  their 
proper  forms  may  be  clearly  recognized,  the  mineral  is  crystallized. 
When  we  have  a  confused  mass  showing  crystal-faces  or  planes  and 
cleavage  planes,  but  no  perfect  crystals  (rock-salt  and  white  marble), 
it  is  crystalline  or  massive.  When  crystalline  form  and  cleavage  are 
both  entirely  wanting  to  the  unaided  eye,  but  the  specimen  exhibits 
the  phenomenon  of  double  refraction  when  a  thin  section  is  viewed 
by  polarized  light  (chalcedony),  it  is  cryptocrystalline  or  compact. 


When-  ftiinesral  matter  is.  entirely  devoid  of  crystallization  (opal  and 
obsidian),  it  IS  dfe^cfibe-d  as  amorphous  or  wholly  unindividualized. 
Forms  of  Crystals. —  This  is  the  most  important  and  at  the  same 
time  the  most  difficult  section  of  crystallography ;  and  the  student  is 
particularly  recommended  to  refer  to  a  standard  treatise,  such  as 
Dana's  Text-book  of  Mineralogy.  But  little  more  can  be  attempted 
here  than  an  explanation  of  the  terms  used  in  the  Tables.  The 
numerous  forms  of  crystals  are  arranged  in  six  systems,  based  on  the 
relative  lengths,  positions  and  numbers  of  the  axes.  Each  system 
has  a  number  as  well  as  a  name,  and  in  the  Tables  they  are  indicated 
by  the  Roman  numerals. 

I.  Isometric  System. —  The  simplest  form  in  this  system  is  the 
cube,  with  six  square  sides  or  planes.     Then  comes  the  octahedron  with 
eight  triangular  planes,  the  dodecahedron  with  twelve  rhombic  planes, 
the  trigonal  trisoctahedron  with  twenty-four  triangular  (trigonal)  planes, 
the  tetragonal  trisoctahedron  with  twenty-four  quadrangular  (tetragonal) 
planes,  the  tetrahexahedron  with  twenty-four  triangular  planes  arranged 
on  the  plan  of  the  cube  instead  of  the  octahedron,  and  lastly  the  hex- 
octahedron  with  forty-eight  planes.     All  of  these  forms,   except  the 
cube  and  dodecahedron,  may  occur  with  only  half  the  planes  devel- 
oped, giving  what  are  called  hemihedral  (half -faced)  forms,    which 
may  have  distinct  names,  the    hemi-octahedron  being  also  called  the 
tetrahedron,  etc.     In  general,  both  the  number  and  arrangement  of  the 
planes  are  quite  clearly  expressed  in  the  crystallographic  names. 

II.  Tetragonal  System. —  The  square  or  tetragonal  prism  is  the 
simplest  or  fundamental  form  of  this  system.     There  is  also  an  eight- 
sided  or  ditetragonal prism.     The  end  planes  of  the  prisms  are  called 
the  basal  planes.     The  remaining  forms  are  the  square  or  tetragonal 
pyramid,  resembling  the  octahedron  of  the  isometric  system  lengthened 
or  shortened  in  the  direction  of  one  axis,  and  the  ditetragonal  or  eight 
sided  pyramid.     The  crystallographic  pyramid  is  double,  being  equiv- 
alent to  two  geometric  pyramids  placed  together,  base  to  base ;  and 
it  contains,  in  each  case,  twice  as  many  planes  as  the  name  indicates. 

III.  Hexagonal  System. — In  this  system,  as  the  name  implies, 
the  fundamental  form  is  the  hexagonal  prism.     The  holohedral  forms 
are  strictly  analogous  to  those  of  the  tetragonal  system.     Thus  we 
have  the  hexagonal  and  dihexagonal  prisms,  basal  planes,  and  hexa- 
gonal and  dihexagonal  pyramids.     The  most  important  of  the  hemi- 
hedral forms  are  the  hemihexagonal  pyramid  or  rhombohedron,  a  form 
bounded  by  six  rhombic  planes  and  resembling  an  oblique  cube  ;  and 
the  hemidihexagonal pyramid  or  scalenohedron. 

IV.  Orthorhombic  System. —  The  fundamental  form  here  is  the 
ortho  (right)   rhombic  prism,  which  gives   the  name  to   the  system. 
Then  comes  the  right  rectangular  prism,  consisting  of  two  narrow 
planes  called  brachypinacoids  and  two  broad  planes  called  macropina- 
coids.     The  two  end  planes,  as  before,  are  the  basal  planes.     The  eight 
inclined  or  sloping  planes  corresponding  in  position  to  the  orthorhombic 
prism  planes  make  the  orthorhombic  pyramid ';  while  the  four  inclined 
planes  corresponding  to  the  brachy  and  macro  pinacoids,  respectively, 
are  the  brachy  and  macro  domes. 


V.  Monoclinic  System. —  This  system  is  essentially  similar  to 
the  last,  except  that  one  of  the  axial  intersections  is  oblique,  so  that 
the  forms  all  incline  in  one  direction  (monoclinic).     The   prefixes 
of  the  names   pinacoid   and   dome   are   ortho  and  clino,    instead   of 
macro  and  brachy ;  and  we  call  the  prism  and  pyramid  monoclinic, 
instead  of  orthorhombic. 

VI.  Triclinic  System. —  The  forms  of  this  system  are  analogous 
to  those  of  the  fourth  and  fifth  systems ;  but  are  easily  distinguished 
by  the  fact  that  the  angles  are  all  oblique. 

When  all  the  planes  on  a  crystal  are  of  one  kind,  it  is  described 
as  a  simple  form  and  given  one  crystallographic  name.  But  when 
they  are  of  two  or  more  kinds  it  is  called  a  compound  form,  and 
requires  for  its  accurate  description  as  many  crystallographic  names 
as  there  are  kinds  of  planes.  Thus,  on  the  ordinary  crystal  of  quartz 
there  are  two  kinds  of  planes,  and  we  describe  it  as  a  combination 
of  the  hexagonal  prism  and  the  hexagonal  pyramid. 

These  compound  forms  must  be  carefully  distinguished  from  the 
compound  or  twin  crystals.  The  quartz  crystal,  although  described 
as  a  compound  form,  because  there  are  two  forms  or  kinds  of  planes, 
is  a  single,  simple  crystal.  But  if  two  such  crystals  should  grow 
together  in  a  regular  manner,  the  result  would  be  a  double  or  twin 
crystal. 

Structures  of  Crystals. — The  only  topic  that  need  be  noticed  under 
this  head  is  the  regular  splitting  exhibited  by  most  crystals  — 

Crystalline  Cleavage,  which  is  scarcely  less  important  to  the 
student  of  determinative  mineralogy  than  the  external  forms  of  crystals. 

Amorphous  bodies,  such  as  glass  and  opal,  being  essentially  homo- 
geneous, possess  no  planes  of  least  cohesion,  but  are  equally  strong  in 
all  directions.  Consequently,  when  broken  they  yield  fragments  of 
very  irregular  forms.  But  the  regular  molecular  structure  of  crystals, 
as  already  stated,  is  usually  indicated  by  definite  directions  of  easy 
splitting  or  cleavage ;  so  that  the  fragments  present  on  one  or  more 
sides  flat  lustrous  surfaces.  Cleavage  is  independent  of  hardness, 
being  almost  equally  perfect  in  diamond  and  talc,  the  hardest  and 
softest  of  minerals.  The  cleavage  directions  or  planes  are  always 
parallel  to  some  actually  occurring,  or  to  some  possible,  external 
planes  of  the  crystal ;  and  are  usually  limited  to  the  simpler  forms  in 
each  system.  Consequently  it  is  often  possible  to  determine  all  the 
more  important  features  of  the  crystallization  of  a  mineral  from  the 
examination  of  small  cleavage  fragments. 

There  are  different  degrees  of  cleavage.  When  the  mineral  splits 
very  easily,  yielding  smooth  and  brilliant  surfaces,  like  mica,  the 
cleavage  is  perfect  or  eminent;  and  the  inferior  degrees  are  described 
as  distinct,  indistinct  or  imperfect,  interrupted,  in  traces,  difficult,  etc. 

The  different  cleavage  directions  are  named  after  the  external 
planes  of  the  crystals  with  which  they  are  parallel.  Thus,  in  the 
isometric  system  we  have  cubic,  octahedral  and  dodecahedral  cleav- 
ages. The  principal  kinds  of  cleavage  in  the  other  systems  are  the 
prismatic,  basal  and  pyramidal,  besides  the  rhombohedral  cleavage  of 
the  third  system  and  the  pinacoidal  cleavages  of  the  fourth,  fifth  and 
sixth  systems. 


6 

Forms  and  Structures  of  Mineral  Aggregates. —  Minerals  frequently 
occur  in  masses  having  a  more  or  less  definite  external  form  and  in- 
ternal structure,  the  form  and  structure  of  which  are  not  due  wholly, 
if  at  all,  to  crystallization,  *'.  e.,  to  a  regular  geometric  arrangement 
of  the  mineral  molecules,  but  are  the  product,  in  part  at  least,  of 
forces  different  from  those  by  which  crystals  are  made.  These 
masses  or  aggregates  are  sometimes  uncrystalline,  and  are  never 
single  crystals  or  regular  compounds  of  crystals. 

External  Forms  of  Mineral  Masses. —  When  mineral  matter 
is  deposited  in  parallel  layers  on  uneven  surfaces,  the  upper  surface  of 
the  deposit,  like  snow  that  has  fallen  on  uneven  ground,  presents 
smoothly  rounded  hummocks  or  elevations.  If  these  are  small  and 
somewhat  grape-like  in  outline,  the  form  is  described  as  botryoidal. 
When  the  rounded  prominences  are  larger,  the  form  is  called 
mammillary. 

Closely  related  to  these  deposition  forms  are  those  produced  when 
water  holding  mineral  matter  in  solution  falls,  drop  by  drop,  from  an 
overhanging  surface  of  rock.  The  pendant  cone  or  column  thus  pro- 
duced is  called  a  stalactite,  and  the  form  is  described  as  stalactitic. 
The  low  mound  or  layer  made  by  the  water  dripping  from  the  point 
of  a  stalactite  upon  the  rocky  floor  below  is  called  a  stalagmite,  the 
adjective  term  being  stalagmitic.  The  porous  deposits  formed  when 
reeds,  grass,  moss,  and  other  kinds  of  vegetation  are  incrusted  by 
mineral  solutions  is  called  a  tufa,  and  its  form  and  structure  are 
described  as  tufaceous. 

A  rounded  mass  or  nodule  produced  by  the  segregation  of  mineral 
matter  in  the  body  of  a  rock  is  called  a  concretion,  the  form  being 
concretionary.  If  the  concretions  are  small,  about  like  peas,  the 
form  is  called  pisolitic ;  but  if  they  are  as  small  as  mustard  seed  it  is 
oolitic.  Hollow  concretions  are  called  geodes.  The  amygdaloidal 
(almond-like)  form  results  from  the  deposition  of  mineral  matter  in 
the  vesicles  or  steam-holes  of  lava.  In  the  stains  of  iron  arid  man- 
ganese oxides  known  as  dendrite,  in  moss  agate,  often  in  native 
copper,  and  on  a  frosted  window  pane,  we  have  forms  which  are 
called  dendritic,  arborescent  and  mossy.  These  are  usually  more  or 
less  dependent  upon  the  crystallization  ;  and  from  these  we  pass  easily 
to  the  reticulated  and  plumose  forms.  The  native  metals,  especially, 
occur  in  wire-like  or  thread-like  shapes,  and  are  described  as  filiform 
or  capillary ;  while  slender,  needle-like  crystals  are  acicular.  When 
a  surface  is  thickly  set  with  crystals  of  uniform  size,  they  are  described 
as  implanted  crystals ;  and  when  the  implanted  crystals  are  very  small, 
the  form  is  called  drusy. 

Internal  Structures  of  Mineral  Masses.  —  We  have,  first,  the 
different  kinds  of  granular  structure.  The  grains  are  usually  merely 
small,  imperfect  crystals,  and  there  is  a  perfect  gradation  from  the 
most  coarsely  to  the  most  finely  granular  kinds.  When  the  grains 
become  invisible  to  the  naked  eye,  the  structure  is  compact  or  impalpa- 
ble ;  and  when  no  trace  of  a  granular  structure  can  be  detected,  even 
with  the  microscope,  the  mineral  is  glassy  or  vitreous.  In  this  state 
it  may  be  crystalline,  like  vitreous  quartz,  or  amorphous,  like  obsidian. 


The  lamellar  structures  come  next  in  importance.  We  properly 
distinguish  at  the  outset  those  masses  in  which  the  lamination  is 
entirely  independent  of  crystallization,  from  those  in  which  it  is  not. 
In  the  first  class  this  structure  is  commonly  described  as  banded,  and 
in  the  second  a3  foliated.  The  banded  structure  occurs  commonly 
with  the  botryoidal,  stalactitic,  stalagmitic  and  geoditic  forms,  and  the 
layers  may  be  straight  (plane)  or  curved  and  concentric.  The  foli- 
ated  structure,  on  the  other  hand,  is  simply  an  easy  splitting  in  parallel 
planes  due  to  very  perfect  cleavage  in  one  direction.  The  cleavage 
is  usually  basal ;  and  foliation  has  its  best  development  in  the  micas 
and  allied  minerals. 

The  fibrous  structure  is  the  third  principal  kind.  It  also  depends 
upon  the  crystallization ;  for,  as  we  may  usually  regard  the  granular 
masses  as  aggregates  of  short,  thick  crystals ;  the  foliated  masses  as 
aggregates  of  flat,  tabular  crystals ;  so  the  fibrous  masses  may  .be 
regarded  as  examples  of  very  slender,  attenuated  crystals  —  pris- 
matic crystallization  carried  to  an  extreme.  When  the  fibres  are 
large  and  distinct  the  structure  is  called  columnar  or  bladed. 

In  the  tables,  not  only  the  system  in  which  the  mineral  crystallizes, 
but  any  marked  habit  of  crystallization,  and  its  more  characteristic 
uncrystalline  or  massive  forms  are  briefly  indicated. 

The  habit  of  crystallization  is  called  distinctly  prismatic  or  distinctly 
tabular,  etc.,  only  when  the  development  of  these  forms  is  very 
marked,  the  prisms,  for  example,  being  several  or  many  times  longer 
than  thick. 


PHYSICAL  PROPERTIES. 

The  topics  to  be  considered  here  are  those  characteristics  of  min- 
erals depending  upon  their  relations  to  the  physical  forces,  such  as 
cohesion,  elasticity,  light,  heat,  electricity,  etc. 

Cleavage  and  Fracture.  —  When  minerals  are  broken,  if  the 
divisions  are  determined  in  direction  and  character  by  the  crystalliza- 
tion, yielding  smooth,  plane  surfaces  parallel  to  the  external  planes 
of  the  crystal,  the  breaking  is  called  cleavage ;  but  if  the  divisions 
are  independent  of  the  crystalline  form,  and  usually  more  or  less 
irregular,  the  breaking  is  called  fracture. 

Although  cleavage  planes  are  directions  in  crystals  along  which 
the  molecules  separate  readily,  and  cleavage  is,  in  this  respect,  evi- 
dently related  to  cohesion,  yet  it  is  far  more  important  as  a  manifes- 
tation of  the  molecular  structure  of  crystals ;  and  its  characteristics 
have,  therefore,  been  described  in  the  preceding  section  (see  page  5). 
When  the  cleavage  is  perfect,  true  fracture  is  difficult  to  obtain, 
on  account  of  the  strong  tendency  of  the  breaking  to  follow  the 
directions  of  least  resistance,  /.  <?.,  the  cleavage  directions.  The 
most  important  kinds  of  fracture  are:  the  conchoidal,  the  mineral 


8 

breaking  with  curving  concavities  and  convexities  resembling  the 
valve  of  a  shell ;  the  even,  when  the  surface  of  the  fracture  is  approxi- 
mately smooth  ;  the  uneven  ;  the  earthy,  breaking  like  clay  or  chalk  ; 
and  the  hackly,  splintery,  etc.  In  the  Tables,  the  fracture  is  given 
only  where  the  cleavage  is  very  imperfect  or  entirely  wanting. 

Hardness. —  The  hardness  of  a  mineral  is  the  resistance  which 
it  offers  to  abrasion.  Hardness,  however,  is  a  purely  relative  term, 
and  hence  mineralogists  have  found  it  necessary  to  select  certain 
minerals  to  be  used  as  a  standard  of  comparison  for  all  otners.  This 
scale  of  hardness  consists  of  ten  minerals  showing  a  regular  grada- 
tion in  hardness  from  talc,  which  is  one  of  the  softest  of  minerals, 
to  diamond,  the  hardest  of  all  minerals,  as  follows:  i.  Talc; 
2.  Gypsum;  3.  Calcite ;  4.  Fluorite ;  5.  Apatite;  6.  Orthoclase; 
7.  Quartz;  8.  Topaz;  9.  Corundum;  10.  Diamond. 

Arranged  in  this  order,  each  member  of  the  scale  is  harder  than 
(  i.  e.,  will  scratch )  all  that  come  before  it,  and  softer  than  ( /.  e.y 
is  scratched  by  )  all  that  come  after  it.  The  degree  of  hardness  pos- 
sessed by  any  mineral  may  be  determined  by  direct  comparison  with 
the  scale,  and  is  expressed  by  the  number,  rather  than  the  name,  of 
the  member  of  the  scale  to  which  it  corresponds.  Thus,  if  it  does 
not  scratch  orthoclase,  and  is  not  distinctly  scratched  by  orthoclase, 
its  hardness  is  6.  If  it  scratches  fluorite,  but  is  scratched  by  apatite, 
its  hardness  is  between  4  and  5  ;  and  it  is  possible,  by  making  the 
test  carefully,  to  determine  whether  it  is  about  4.25,  4.5,  or  4.75. 

In  the  column  marked  "  H,"  in  the  Tables,  the  exact  hardness  of 
each  species  is  given,  so  that  careful  comparisons  may  be  made  when 
desired.  But  an  examination  of  the  analytical  key  on  the  left 
margin  of  each  table,  or  of  the  general  classification  of  the  Tables 
on  page  25,  will  show  that  the  determinations  are  based  upon  a  scale 
of  hardness  embracing  only  five  degrees,  as  follows  :  — 

1.  Very  soft  (below  2.5)  ;  can  be  scratched  with  the   nail,  or  very 

easily  with  the  knife. 

2.  Soft    (2.5-4)  ;   cannot    be    scratched    with    the   nail,    but   easily 

scratched  with  the  knife. 

3.  Hard  (4-6)  ;  can  be  scratched  with  the  knife,  but  not  easily. 

4.  Very  hard  (6-7 )  ;  cannot  be   scratched  distinctly   with  the  knife, 

but  is  scratched  by  quartz. 

5.  Adamantine  (above  7)  ;  cannot  be  scratched  by  quartz. 

The  figures  in  the  parentheses  give  the  corresponding  degrees  of 
the  regular  scale. 

The  great  advantage  of  this  scale  is  its  convenience,  combined 
with  a  reasonable  degree  of  accuracy.  The  adamantine  minerals,  or 
those  having  hardness  above  7,  are  all  found  in  one  small  group  at 
the  very  end  of  the  Tables.  Hence,  in  nearly  all  cases  the  quartz 
will  not  be  required,  the  knife  and  thumb-nail  being  sufficient ;  and 
a  little  practice  will  enable  the  student  to  determine  whether  a 
mineral  which  can  be  scratched  with  the  knife  scratches  easily  or 
with  difficulty.  The  doubtful  or  variable  minerals  are  repeated  in 
all  sections  of  the  Tables  to  which  students  would  be  likely  to  assign 


them.  It  is  important,  however,  to  note  that  beginners  usually  over- 
estimate the  hardness,  especially  of  the  malleable  and  semi-brittle 
minerals ;  and  that  a  sharp  angle  will  usually  slightly  scratch  a  flat 
surface  of  the  same  mineral.  The  student  will  also  learn  to  make 
allowance  for  foreign  substances  or  impurities  ;  and  for  the  surface 
alteration  or  decomposition  of  minerals. 

In  many  cases,  however,  the  specimens  to  be  tested  are  so  rough, 
friable  or  small  as  to  make  the  determination  of  the  hardness  in  the 
usual  way,  by  scratching  the  mineral  itself  with  a  hard  point,  unsatis- 
factory. It  is  proposed,  therefore,  to  give  greater  precision  to  the 
determinations  by  reversing  the  tests  and  using  the  mineral  to  scratch 
polished  surfaces  of  suitable  hardness.  Polished  surfaces,  it  is  well 
known,  are  extremely  sensitive  to  abrasion,  /'.  <?.,  a  slight  scratch  is 
readily  detected  ;  and  the  scratching  can  be  done  with  very  minute 
grains. 

The  polished  surfaces  should  have  hardness  about  2.5,  4,  6,  and 
7,  so  as  to  mark  the  divisions  between  the  five  degrees  of  the  abbre- 
viated scale, —  very  soft,  soft,  hard,  very  hard,  and  adamantine  ;  and 
biotite  (black  mica),  fluorite,  orthoclase,  and  agate  or  quartz  are 
specially  recommended  for  this  purpose,  although  the  harder  kinds 
of  glass  may  be  conveniently  substituted  for  the  orthoclase.  Pro- 
vided with  such  a  scale,  the  student  can  readily  refer  any  undecom- 
posed  mineral  to  its  proper  division.  For  example,  if  it  does  not 
scratch  the  biotite,  it  is  very  soft ;  if  it  scratches  the  fluorite,  but 
does  not  scratch  the  orthoclase,  it  is  hard ;  if  it  scratches  the  agate, 
it  is  adamantine,  and  so  on. 

With  reasonable  care,  a  square  inch  of  polished  surface  will  suffice 
for  many  determinations,  and  the  scale  need  not  be  frequently 
renewed  ;  although  with  a  piece  of  biotite  of  suitable  thickness  the 
surface  may  be  readily  and  repeatedly  renewed  by  cleavage. 

Tenacity. —  All  solid  minerals  may  be  classed  as  either  brittle 
or  flexible.  Brittle  minerals,  to  which  class  the  majority  belong,  are 
those  whose  forms  cannot  be  sensibly  distorted  without  rupture. 
The  degree  of  cohesion,  however,  varies  greatly ;  some  brittle  min- 
erals being  very  rigid  or  strong  (tough)  and  breaking  with  great 
difficulty,  like  corundum ;  while  in  the  typical  brittle  minerals,  such 
as  quartz  and  calcite,  the  cohesion  is  less  and  a  moderate  blow 
suffices  to  break  them.  But  the  minimum  cohesion  is  found  in  the 
friable  minerals,  which  are  at  once  very  brittle  and  very  easily  broken. 
Brittle  minerals,  in  other  words,  are  those  which  break  suddenly 
under  a  blow,  and  whether  the  blow  needs  be  light  or  heavy  is 
immaterial. 

Flexible  minerals,  on  the  other  hand,  are  those  whose  forms  can 
be  sensibly  distorted  without  rupture.  All  flexible  minerals  are  also 
sectile,  i.  e.,  can  be  cut  without  .breaking  or  crumbling.  All  brittle 
minerals  are  elastic,  and  the  elastic  flexible  minerals,  such  as  mica, 
are  not  flexible  in  pieces  of  moderate  thickness.  The  typical  flexible 
minerals  are  malleable  and  ductile  as  well  as  sectile.  As  in  the 
brittle  class,  the  degree  of  cohesion  varies  greatly.  This  is  seen  by 
comparing  iron  and  copper  with  gypsum  and  talc. 


10 

Specific  Gravity.  —  By  the  specific  gravity  of  a  mineral  we 
mean  its  weight  compared  with  the  weight  of  an  equal  volume  of 
water.  The  specific  gravity  of  solid  bodies  is  usually  determined  as 
follows :  The  specimen  is  first  weighed  carefully  on  a  good  balance  ; 
it  is  then  suspended  from  one  pan  of  the  balance  by  a  thread  or  fine 
wire  in  a  glass  of  water,  and  while  hanging  freely  and  completely 
immersed,  its  weight  is  taken  again.  The  second  weight  is  sub- 
tracted from  the  first.  The  difference,  or  loss  by  immersion,  is  the 
weight  of  a  volume  of  water  equal  to  that  of  the  specimen ;  and  by 
dividing  this  weight  into  the  first  weight  of  the  specimen,  the  desired 
ratio  is  obtained.  For  example,  a  piece  of  quartz  weighs  25  grains 
in  air,  and  15.57  grains  in  water.  25  — 15.57=9.43  grains,  the 
weight  of  an  equal  volume  of  water.  25  -^-9.43  =  2.65,  the  specific 
gravity  of  quartz. 

Minerals  exhibit  a  wide  range  in  specific  gravity,  from  petroleum, 
which  floats  on  water,  to  gold,  which  is  nearly  twenty  times  heavier 
than  water.  Very  few  minerals,  however,  are  heavier  than  iron 
(7.5)  and  still  fewer  are  lighter  than  sulphur  (2),  the  great  majority 
falling  between  2.5  and  5.  But,  notwithstanding  this  narrow  range, 
specific  gravity  is  such  a  fundamental,  constant,  and  distinctive 
property  that  a  special  effort  has  been  made  to  render  it  more  avail- 
able in  determinative  mineralogy  by  devising  a  simple  and  inexpen- 
sive balance  for  its  ready  and  accurate  measurement.  Although 
extremely  simple  in  construction,  this  balance  is  very  sensitive  and 
accurate.  It  consists  of  a  light  wooden  beam  with  the  fulcrum  near 
one  end,  as  in  a  steelyard.  The  bearings  are  fine  needle  points 
resting  in  shallow  glass  cups,  so  that  the  movement  is  practically 
devoid  of  friction ;  and  suitable  adjusting  and  regulating  screws  are 
provided.  From  the  short  end  of  the  beam  two  small  pans  are  sus- 
pended, one  below  the  other.  The  lower  pan,  which  is  attached  to 
the  upper  one  by  a  single  fine  platinum  wire,  hangs  freely  in  a  small 
beaker  or  glass  of  water.  The  longer  end  of  the  beam  is  provided 
with  a  millimeter  scale,  measuring  distances  from  the  fulcrum.  No 
definite  weights  are  used,  the  relative  weights  of  the  mineral  in  and 
out  of  water  being  all  that  is  essential ;  and  the  balance  is,  therefore, 
provided  with  several  small  counterpoises  in  the  form  of  riders. 
Each  specific  gravity  determination  is  made  with  a  single  counter- 
poise, the  modus  operandi  being  as  follows  :  — 

The  mineral  is  placed  in  the  upper  pan,  balanced  by  a  suitable 
counterpoise,  and  the  position  of  the  counterpoise  on  the  millimeter 
scale  carefully  noted.  The  specimen  is  then  transferred  to  the  lower 
pan,  the  counterpoise  readjusted,  and  its  position  noted  again. 
Subtracting  the  second  reading  from  the  first  and  dividing  the  first 
reading  by  the  difference  gives  the  desired  result.  After  a  few  trials, 
an  accurate  specific  gravity  determination  should  not  require  more 
than  two  or  three  minutes. 

Luster. — By  the  luster  or  glance  of  a  mineral  is  meant  the  quantity 
and  quality  of  light  reflected  by  it,  as  determined  by  the  character 
or  minute  structure  of  its  surface.  Variations  in  the  nature  of  the 
reflecting  surface  produce  different  kinds  of  luster ;  and  variations  in 


the  quantity  of  light  reflected,  i.  e.,  in  the  polish  of  the  surface,  pro- 
duce different  degrees  of  luster. 

The  two  principal  kinds  of  luster  are  the  metallic  and  non-metallic. 
The  metallic  luster  is  the  luster  of  all  true  metals,  such  as  silver, 
copper,  etc.,  and  of  most  minerals  in  which  metallic  elements  pre- 
dominate. When  the  luster  is  not  distinctly  or  perfectly  metallic,  it 
is  called  sub-metallic.  '^\it  adamantine  luster  is  intermediate  between 
the  metallic  and  non-metallic  lusters.  It  is  well  shown  in  but  few 
minerals,  diamond  being  the  most  perfect  example. 

Most  of  the  minerals  in  which  the  non-metallic  elements  predomi- 
nate have  a  non-metallic  luster.  This  is  by  far  the  most  common 
luster,  only  about  one-fifth  of  the  known  minerals  which  have  a 
distinct  luster  being  either  metallic  or  adamantine.  The  non-metallic 
luster  embraces  several  varieties,  which  are  named  in  the  order  of 
their  importance. 

The  vitreous  is  the  luster  of  glass,  and  of  all  minerals  similar  to 
glass  in  appearance,  such  as  quartz,  calcite,  etc.  The  resinous  luster 
is  seen  in  resins,  of  which  the  native  mineral  copalite  is  an  example ; 
it  is  also  well  exhibited  in  sulphur  and  sphalerite.  The  pearly  luster, 
i.e.,  the  luster  of  pearl,  is  well  shown  only  in  minerals  having  a 
foliated  or  scaly  structure,  in  other  words,  very  perfect  cleavage  in 
one  direction,  such  as  talc,  mica,  and  gypsum.  The  silky  or  satiny 
luster,  like  the  pearly,  is  determined  by  the  structure,  being  observed 
only  in  finely  fibrous  minerals.  Fibrous  gypsum  or  satin-spar  is 
the  best  illustration,  although  fibrous  calcite,  serpentine,  malachite, 
asbestus,  etc.,  are  nearly  as  good.  The  greasy  and  waxy  lusters  are 
most  common  in  certain  amorphous  minerals,  such  as  serpentine. 

The  degrees  of  luster  are  expressed  as  follows :  — 

The  luster  is  splendent  when  the  surface  reflects  brilliantly,  giving 
well  defined  images.  It  is  shining  when  the  reflected  image  is  not 
well  defined.  When  there  is  a  general  reflection  from  the  sur- 
face, but  no  recognizable  image,  the  luster  is  glistening.  If  the 
reflection  is  very  imperfect,  and  chiefly  from  minute  points,  the  luster 
\§  glimmering.  A  mineral  is  described  as  dull  when  there  is  a  com- 
plete absence  of  luster,  /'.  ^.,  when  no  light  is  regularly  reflected,  as 
in  earthy  minerals. 

In  using  these  Tables,  or  almost  any  determinative  system,  it  is  a 
matter  of  the  first  importance  to  be  able  to  recognize  the  different 
kinds  of  luster,  and  especially  to  know  whether  or  not  the  lustre  of  a 
mineral  is  metallic.  This  is  the  first  question  to  be  answered  with 
every  species.  One  aid  to  answering  it  correctly  is  found  in  the 
perfect  opacity  of  all  metallic  minerals.  If  the  finest  splinter  or  the 
thinnest  scale  of  the  mineral  in  hand  appears  in  the  slightest  degree 
translucent,  when  held  up  to  the  light,  it  cannot  be  metallic.  But 
the  converse  statement  is  not  always  true,  since  some  non-metallic 
minerals  will  appear  quite  opaque,  except  in  the  extremely  thin 
sections  prepared  with  considerable  labor  for  miscroscopic  examina- 
tion. 

The  darker  colored  and  nearly  opaque  non-metallic  minerals  are 
among  those  most  likely  to  be  referred  to  the  wrong  luster  ;  and  many 


12 

of  these,  as  well  as  the  most  of  the  sub-metallic,  adamantine  and  dull 
species,  have,  in  consequence,  been  placed  in  both  divisions  of  the 
Tables. 

Diaphaneity. —  The  light  transmitted  by  minerals  varies  in 
amount  within  wide  limits  ;  or,  in  other  words,  of  the  light  received, 
and  not  reflected,  more  or  less  may  be  absorbed.  The  following 
degrees  of  diaphaneity  are  usually  recognized. 

Transparent,  when  the  outline  of  an  object  seen  through  the  min- 
eral is  perfectly  distinct.  Subtransparent  or  semitransparent,  when 
objects  are  seen  but  the  outlines  are  not  distinct.  Translucent,  when 
light  is  transmitted  but  objects  are  not  seen.  Subtrans lucent  or 
semitranslucent,  when  merely  the  edges  of  the  specimen  transmit  light 
or  are  translucent.  Opaque,  when  the  mineral  transmits  no  light  in 
ordinary  specimens. 

The  diaphaneity  is  of  very  little  value  in  the  determination  of 
minerals,  except  as  an  aid  in  deciding  whether  or  not  the  luster  is 
metallic;  for  it  is  exceedingly  variable  and  inconstant,  the  same 
species,  or  even  the  same  specimen,  often  showing  every  degree 
from  transparent  to  opaque.  No  other  property  of  non-metallic 
minerals  is  affected  in  an  equal  degree  by  slight  impurities  and 
imperfections.  In  fact,  if  all  mineral  bodies  were  perfectly  pure  and 
homogeneous  we  should  probably  find  that  the  metallic  species  are 
all  opaque,  and  the  non-metallic  species  are  all  transparent. 

Color. —  The  color  of  a  mineral  is  a  measure  of  its  power  of 
absorbing  different  portions  of  the  light  that  passes  through  it  or 
falls  on  its  surface.  If  no  light  is  absorbed,  or,  more  correctly,  if  all 
the  rays  of  the  spectrum  are  absorbed  equally,  the  color  is  white. 
If  the  red  rays  are  absorbed,  the  color  is  green,  and  so  on.  The 
color  is  always  a  mixture  of  the  rays  that  are  not  absorbed. 

The  colors  of  metallic  minerals  are  usually  constant  and  afford 
important  aid  in  distinguishing  species ;  and  the  same  is  true  of  a 
few  of  the  non-metallic  minerals.  The  great  majority  of  the  non- 
metallic  species,  however,  would  be  white  if  perfectly  pure  ;  and  since 
the  actual  colors  depend  upon  the  kind  and  quantity  of  impurity 
present,  they  are  extremely  variable. 

The  different  varieties  of  color  in  both  metallic  and  non-metallic 
minerals  are  easily  recognized  ;  but  a  far  more  important  distinction 
is  that  between  the  color  of  the  solid  mineral  and  the  streak  or  the 
color  of  the  mineral  in  the^form  of  a  fine  powder.  The  color  of  the 
powder  is  called  the  streaK  simply  because  it  is,  in  general,  most 
conveniently  observed  by  scratching  the  surface  of  the  mineral,  or 
by  marking  with  it  upon  a  white  surface  of  suitable  hardness.  In 
either  way,  we  produce  a  line  or  streak  of  the  powdered  mineral 
sufficient  to  give  its  color. 

With  the  most  truly  metallic  minerals,  including  the  metals  and 
such  compounds  as  galenite,  stibnite,  etc.,  the  streak  is  like  the 
color,  or  darker,  owing  to  the  dispersion  of  the  light  by  the  powder. 
In  all  other  cases,  the  streak  is  either  the  same  as  the  color,  as  with 
white  or  gray  minerals,  and  such  colored  species  as  realgar  and  cin- 
nabar, or  it  is  lighter  than  the  color,  as  with  hematite  and  limonite 


13 

and  the  great  majority  of  colored  non-metallic  minerals.  In  general, 
the  streak  may  be  regarded  as  the  color  of  the  mineral  when  very 
thin  pieces  are  viewed  by  transmitted  light.  The  colors  of  most 
non-metallic  minerals  are  due  to  the  presence  of  opaque  impurities ; 
and  in  very  thin  forms  these  are  insufficient  to  affect  the  true  or 
essential  color. 

The  malleable  and  semi-malleable  minerals,  such  as  copper  and 
antimony,  are  not  easily  pulverized  by  scratching;  and  the  mark 
made  upon  them  simply  shows  the  color  of  the  polished  surface. 
For  this  reason,  and  also  because  in  many  cases  the  mineral  itself 
does  not  present  a  suitable  ground  on  which  to  observe  the  color  of 
its  powder,  the  streak  is  most  satisfactorily  determined  by  marking 
with  the  mineral  itself  upon  a  white  surface.  The  streak  of  very 
soft  minerals  is  easily  obtained  by  marking  on  paper,  the  lead-pencil 
mark  being  the  streak  of  graphite.  For  all  but  very  hard  minerals, 
a  surface  of  unglazed  porcelain  may  be  used ;  but  the  best  of  all 
streak-stones  is  a  small,  smooth  slab  of  Arkansas  stone,  —  a 
compact,  white  form  of  quartz.  This  answers  for  all  but  the 
adamantine  minerals ;  and  for  these  no  streak-stone  is  required, 
since  they  all  have  a  white  streak.  In  the  construction  of  the 
Tables,  it  has  been  assumed  that,  in  general,  a  streak-stone  will  be 
used  in  the  determination  of  this  important  property. 

Any  merely  superficial  color,  or  color  due  to  exposure  to  the  air 
or  weather,  is  called  tarnish.  A  mineral  is  described  as  tarnished 
when  the  surface  color  is  different  from  that  on  a  fresh  fracture.  The 
tarnish  is  often  irised  or  marked  by  various  prismatic  colors,  which 
are  explained  as  due  to  interference  of  light  caused  by  a  film  cover- 
ing the  mineral.  This  superficial  film  or  layer  may  be  the  result  of 
oxidation  or  other  alteration  of  the  mineral  itself,  or  it  may  be  a  thin 
incrustation  of  some  foreign  substance. 

Fusibility.  —  It  is  hardly  practicable  to  determine  with  a  ther- 
mometer the  melting  temperature  of  minerals,  and  the  exact  tem- 
perature of  fusion  is  known  for  only  a  few  species ;  but  mineralogists 
are  usually  satisfied  with  knowing  the  relative  fusing  points  of  the 
different  species.  The  relative  fusibility  is  determined  by  com- 
parison with  six  species  which  have  been  chosen  as  a  scale  of 
fusibility.  These,  beginning  with  the  most  readily  fusible,  are : 
i.  Stibnite ;  2.  Natrolite ;  3.  Garnet;  4.  Actinolite ;  5.  Orthoclase ; 
6.  Bronzite  ;  and  we  may  add  7.  Quartz.  The  fusibility  of  a  mineral 
is  determined  by  heating  a  fine  splinter  or  fragment  in  the  forceps  or 
on  charcoal  with  the  oxidizing  blowpipe  flame.  If  it  fuses  as  readily 
as  natrolite,  it  is  2,  if,  like  quartz,  it  cannot  be  even  rounded  on  the 
thinnest  edges,  it  is  7,  and  so  on. 

It  is  very  important  that  the  fusibility  should  be  tested  with  very 
fine  splinters  or  scales.  When  this  precaution  is  observed,  stibnite 
and  natrolite  are  readily  melted  to  liquid  globules,  and  garnet  with  a 
stronger  heat ;  but  with  actinolite,  and  still  more  with  orthoclase  and 
bronzite,  the  evidence  of  fusion  is  the  rounding  of  the  sharp  edges 
of  the  splinters.  A  mere  swelling  up  or  intumescence  of  a  mineral 
should  not  be  mistaken  for  fusion. 


Magnetism.  —  But  few  minerals  are  sensibly  affected  by  an 
ordinary  magnet ;  and  these  are  the  species  containing  the  largest 
proportions  of  the  strongly  magnetic  element  —  iron.  The  degree 
of  magnetism  is  usually  proportional  to  the  percentage  of  iron,  being 
greater  in  magnetite  than  in  any  other  mineral  except  pure  iron. 
Where  the  magnetism  is  weak,  it  can  only  be  detected  by  first  finely 
pulverizing  the  mineral. 

Touch  or  Feel.  —  This  is  described  as  meagre  (chalk,  clay,  etc.), 
harsh,  rough,  smooth,  unctuous,  and  greasy. 

Taste.  —  A  few  minerals,  being  readily  soluble,  have  a  distinct 
taste.  The  principal  kinds  of  taste  mentioned .  are  the  astringent, 
cooling,  sour,  bitter,  saline,  and  alkaline. 

Odor  or  Smell.  —  Solid  minerals  are  usually  devoid  of  odor 
unless  subjected  to  some  special  treatment,  as  heating,  rubbing, 
moistening,  etc.  The  principal  kinds  of  odor  are  the  sulphurous, 
arsenical,  argillaceous,  and  fetid. 


CHEMICAL  PROPERTIES. 

What  we  have  to  consider  here,  chiefly,  is  the  characteristic  chem- 
ical behavior  of  the  common  minerals,  and  especially  of  their  prin- 
cipal constituent  elements.  A  systematic  account  of  the  composition 
and  chemical  relations  of  minerals  would  be  out  of  place  in  a  work 
of  this  kind ;  but  there  is  one  general  principle  of  such  fundamental 
importance  in  determinative  mineralogy  as  to  demand  the  attention 
of  the  student  at  the  very  outset.  This  is  the  relation  of  the  composition 
to  the  physical  properties  of  minerals.  The  comparison  of  almost  any 
mineral  with  the  chemical  elements  of  which  it  is  composed  shows 
that  the  properties  of  minerals  are  often  very  distinct  from  those  of 
their  constituent  elements.  Thus,  the  common  mineral  pyrite  is 
composed  of  sulphur  and  iron,  and  in  its  general  aspect  it  resembles 
neither  of  these  elements ;  but  a  closer  comparison  shows  that  most 
of  its  properties  may  be  observed  in  them ;  for  it  is  yellow  and  brittle 
like  sulphur,  and  metallic,  hard  and  heavy  like  iron.  Its  specific 
gravity  is  almost  an  average  of  that  of  the  two  elements.  In  general, 
the  contrast  between  minerals  and  their  component  elements  is  more 
strongly  marked  with  the  comparatively  superficial  properties,  like 
color,  than  with  the  more  fundamental  properties,  such  as  form, 
density,  luster,  etc.  The  latter  are,  in  a  very  large  degree,  the 
average  of  the  properties  of  the  elements.  Thus  the  minerals  in 
which  heavy,  metallic  elements  predominate,  such  as  galenite,  etc., 
are  themselves  heavy  and  have  usually  a  metallic  luster;  while 
minerals  composed  chiefly  of  light,  non-metallic  elements,  such  as 
quartz,  etc.,  are  characterized  by  a  low  specific  gravity  and  non- 
metallic  luster.  In  accordance  with  this  principle,  we  find  that  only 
those  minerals  are  magnetic  which  are  richest  in  iron,  the  magnetism 
increasing  with  the  percentage  of  iron ;  and  that,  water  being  one  of 


is 

the  lightest  and  softest  of  mineral-constituents,  the  hydrous  species 
are  lighter  and  softer  than  anhydrous  species  of  otherwise  similar 
composition. 


General  Blowpipe  and  Chemical  Tests, 

Certain  standard  tests  recur  so  frequently  in  the  Tables  that  the 
student  is  recommended  to  acquire  some  familiarity  with  the  modus 
operandi  of  each,  and  the  general  reactions  which  it  yields,  before 
proceeding  to  the  more  special  tests  for  the  indentification  of  the 
particular  constituents  of  minerals. 

Heating  in  the  Closed  Tube.  —  The  mineral  should  be  in  the 
form  of  powder  or  fine  grains  ;  and  the  bulk  of  a  kernel  of  wheat 
will  be  sufficient  in  most  cases.  This  is  placed  in  the  bottom  of  a 
hard  glass  tube  three  inches  long  and  closed  at  one  end.  This  end 
of  the  tube  may  be  heated  by  directing  the  blowpipe  flame  against 
it,  or  more  easily  by  holding  it  in  the  flame  of  the  alcohol  lamp  or 
Bunsen  gas  burner.  The  heat  is  applied  gently  at  first,  and  then 
more  strongly  if  the  reaction  seems  to  demand  it.  The  most  essen- 
tial feature  of  this  test  is  that  the  mineral  is  heated  nearly  out  of 
contact  with  the  air ;  and  the  principal  changes  or  reactions  observ- 
able are  (i)  fusion,  and  (2)  the  formation  of  a  sublimate  in  the 
upper  part  of  the  tube.  Few  minerals  are  melted  ;  and  the  only 
minerals  yielding  sublimates  are  those  that  are  volatile  or  contain 
volatile  constituents,  such  as  sulphur,  arsenic,  mercury,  water,  etc. 

Heating  in  the  Open  Tube. — The  mineral,  preferably  in  the 
form  of  one  or  several  small  grains,  or  of  powder  if  it  decrepitates,  is 
placed  in  a  tube  of  hard  glass  three  inches  long  and  open  at  both 
ends,  the  best  position  being  three-fourths  of  an  inch  from  one  end ; 
and  this  point  is  then  heated  in  the  same  manner  as  the  bottom  of 
the  closed  tube,  the  tube  being  inclined  as  steeply  as  may  be  without 
having  the  mineral  slide  out.  A  current  of  air  is  thus  caused  to  pass 
over  the  mineral  while  it  is  ignited,  and  the  conditions  are  favorable 
for  oxidation.  The  most  important  reactions  are  (i)  the  character- 
istic odors  afforded  by  sulphides  and  arsenides,  and  (2)  the  subli- 
mates formed  in  the  upper  part  of  the  tube  and  consisting  chiefly  of 
the  oxides  of  the  same  substances  forming  sublimates  in  the  closed 
tube.  Sulphurous  and  other  acid  vapors  are  given  off  which  do  not 
condense  on  the  walls  of  the  tube  but  are  recognized  by  the  red- 
dening of  a  slip  of  moistened  blue  litmus  paper  inserted  at  the  upper 
end  of  the  tube. 

Heating  on  Charcoal.  —  The  mineral,  in  about  the  same  quan- 
tity as  before,  is  placed  in  a  shallow,  saucer-shaped  cavity  excavated 
near  one  end  of  a  suitable  piece  of  charcoal.  The  charcoal  is  held 
so  that  the  flame  can  be  directed  upon  the  mineral  with  the  blow- 
pipe. If  the  mineral  decrepitates  or  flies  awray,  it  may  be  finely 
pulverized  and  made  into  a  paste  with  water,  and  then  heated  grad- 
ually until  the  mass  coheres. 


The  principal  phenomena  to  be  observed  are  :  (i)  The  odors  of 
burning  sulphur  and  arsenic,  the  latter  resembling  the  odor  of  garlic. 
These  are  afforded  by  the  elements  and  by  sulphides  and  arsenides. 
(2)  Fusion.  (3)  In  the  oxidizing  flame,  the  metals  are  oxidized  and 
characteristic  sublimates  or  coatings  of  the  oxides  are  formed  on  the 
charcoal,  which  may  be  recognized  by  their  color,  extent,  and  degree 
of  volatility.  (4)  In  the  reducing  flame,  several  metals  are  readily 
reduced  to  the  metallic  state,  especially  if  carbonate  of  soda  is  added 
to  the  pulverized  minerals,  and  many  compounds  of  iron  become 
magnetic. 

Heating  in  the  Forceps.  —  If  possible,  a  minute,  slender 
fragment  or  splinter  should  be  held  by  its  larger  end  with  a  fine 
point  projecting  well  beyond  the  end  of  the  forceps,  so  that  it  may 
be  introduced  into  the  tip  of  the  blue  or  oxidizing  flame  without 
heating  the  forceps.  If  the  mineral  decrepitates  so  that  it  cannot  be 
held  in  the  forceps,  it  may  be  finely  pulverized,  moistened  with  clean 
water,  and  supported  on  a  loop  of  platinum  wire.  If  it  fuses  very 
readily,  or  is  of  such  nature  as  to  attack  the  forceps,  it  must  be 
supported  on  charcoal. 

The  phenomena  to  be  observed  are  :  ( i )  The  degree  of  fusibility 
of  minerals.  If  the  fine  point  melts  into  a  round  globule,  it  is  readily 
fusible  ;  if  it  is  only  slightly  rounded  on  the  end,  it  is  difficultly  fusible, 
and  so  on.  For  greater  precision,  the  behavior  of  the  mineral 
should  be  compared  with  that  of  similar  splinters  of  the  minerals 
forming  the  scale  of  fusibility.  (2)  The  colors  imparted  to  the 
flame  by  minerals.  These  are  often  very  characteristic,  and  form  a 
beautiful  and  delicate  test  for  the  following  elements  :  All  compounds 
of  sodium  yield  a  bright  reddish  yellow  flame.  Potassium  in  most  of 
its  compounds,  tinges  the  flame  bluish  violet.  Lithium  gives  a  pur- 
plish red,  calcium  a  yellowish  red,  and  strontium  a  pure  red,  color  to 
the  flame.  Barium,  copper,  phosphoric  acid,  and  boric  acid  give 
different  shades  of  green.  But  the  chloride  of  copper  colors  the  flame 
azure-blue.  The  green  colors  imparted  to  the  flame  by  phosphorus 
and  boron  compounds  are  intensified  if  the  mineral  is  first  heated, 
then  moistened  with  sulphuric  acid  and  heated  again.  Hydrochloric 
acid  gives  a  similar  result  with  compounds  of  barium,  strontium,  and 
copper.  (3)  The  colors  imparted  to  the  minerals  themselves,  when 
they  are  first  moistened  with  a  solution  of  nitrate  of  cobalt  and  then 
strongly  heated.  Alumina  compounds  become  blue,  zinc  oxide  green, 
and  magnesia  compounds  flesh-red.  This  test  is  only  adapted  for  use 
with  infusible  minerals,  because  all  minerals  fusible  to  a  clear  glass 
form  a  smalt,  or  cobalt-blue  glass  with  cobalt  solution.  A  blue, 
infusible  mass  is  necessary  to  prove  the  presence  of  alumina. 

Fusion  with  Borax  and  Salt  of  Phosphorus. —  The  tests 
with  these  reagents  are  most  conveniently  made  on  a  short  piece  of 
platinum  wire,  one  end  of  which  is  bent  into  a  loop  one-tenth  of  an 
inch  in  diameter.  The  loop  is  heated  to  redness  and  dipped  into 
the  pulverized  flux  ;  the  portion  which  adheres  to  the  wire  is  fused 
by  the  blowpipe  flame ;  and  this  process  is  repeated  until  a  full 
round  bead  of  the  fused  flux  is  formed.  The  salt  of  phosphorus  con- 


tains  so  much  water  of  crystallization  that  it  is  very  fluid  when  first 
fused  ;  and  until  the  water  has  evaporated  the  wire  must  be  manipu- 
lated carefully  to  prevent  the  bead  from  falling  off.  When  the  bead 
is  complete,  and  while  it  is  still  hot,  it  is  touched  to  the  pulverized 
mineral,  so  that  a  small  portion  of  the  latter  adheres.  The  bead  is 
then  strongly  heated,  usually  with  the  oxidizing  flame,  until  the 
mineral,  if  soluble,  is  completely  dissolved  in  the  bead.  These  tests 
are  especially  adapted  to  the  detection  of  the  various  metallic  oxides ; 
and  the  chief  phenomenon  to  be  observed  is  the  color  imparted  to 
the  bead  or  glass  by  the  oxide.  For  a  complete  account  of  the 
reactions  afforded  by  these  tests  the  student  is  referred  to  the  more 
extended  works  on  blowpipe  analysis.  It  is  very  important  that  any 
mineral  known  or  suspected  to  contain  sulphur  or  arsenic  should  be 
carefully  roasted  (oxidized)  on  charcoal  before  being  added  to  the 
bead,  since  the  bead  tests  give  significant  results  only  with  oxides. 

Alkaline  Reaction.  —  A  fragment  of  the  mineral  is  strongly 
heated  in  the  forceps  or  on  charcoal,  and  then  placed  upon  a  strip 
of  red  litmus  paper  and  moistened  with  a  drop  of  water.  If  the 
color  of  the  paper  is  changed  to  blue,  the  reaction  is  alkaline.  This 
is  a  valuable  test  for  the  alkalies  and  alkaline  earths. 

Dissolving  in  Acid.  —  Hydrochloric  (muriatic)  acid  answers  in 
most  cases,  nitric  and  sulphuric  acids  being  rarely  required.  The 
acid  should  be  used  full  strength,  except  when  dilute  acid  is  espe- 
cially called  for;  and  it  is  very  important,  especially  with  silicates, 
that  the  mineral  to  be  tested  should  be  in  the  form  of  an  impalpable 
powder.  The  behavior  of  minerals  with  acids  is  most  conveniently 
observed  in  the  test  tube.  A  small  quantity  of  the  pulverized  mineral 
is  placed  in  the  bottom  of  the  tube,  covered  with  one  or  two  inches 
of  acid,  and  heat  applied  gently  until  the  acid  boils.  The  mineral 
may  dissolve  quietly,  or  with  effervescence  (carbonates  and  sul- 
phides) ;  and  it  may  impart  a  more  or  less  characteristic  color  to  the 
solution.  Silicates  are  either  not  attacked  by  acid,  decomposed 
without  gelatinizing,  or  decomposed  with  the  separation  of  silica  in 
the  form  of  a  stiff  jelly.  T 


List   of  the   Principal  Constituents  of  Minerals,  with   the  Tests   em- 
ployed in  the  Tables  for  the  Detection  of  Each. 

The  substances  are  arranged  alphabetically,  for  convenience  of 
reference ;  and  the  student  is  expected  to  turn  to  this  and  the  pre- 
ceding section  for  full  explanations  of  the  tests  indicated  in  the 
Tables. 

Alumina  may  be  readily  and  certainly  recognized  in  any  infusible 
and  light-colored  minerals,  of  which  it  is  an  important  constituent,  by 
the  beautiful  blue  color  which  they  assume  when  strongly  ignited 
and  then  moistened  with  cobalt  solution  and  ignited  again.  Very 
hard  minerals,  like  diaspore  and  corundum  must  be  finely  pulverized. 


i8 

Antimony  and  most  of  its  compounds  fuse  and  yield  dense  white 
fumes  of  antimony  oxide  when  heated  on  charcoal.  The  oxide 
partially  condenses  on  the  coal,  forming  an  extended  white  coating, 
which  is  volatile  in  the  blowpipe  flame.  A  white  volatile  sublimate 
of  antimony  oxide  is  also  formed  in  the  open  tube. 

Arsenic  and  nearly  all  of  its  compounds  yield  a  sublimate  of 
metallic  arsenic  in  the  closed  tube,  and  a  white  crystalline  volatile 
sublimate  of  arsenious  acid  in  the  open  tube.  On  charcoal,  this 
element  is  recognized  by  the  abundant  gray  smoke,  the  strong  garlic 
odor,  and  the  extremely  volatile  gray  coating  which  it  forms  on  the 
coal. 

Baryta  is  recognized  by  the  yellowish  green  color  imparted  to 
the  blowpipe  flame  by  all  of  its  compounds  except  silicates. 

Bismuth  fuses,  volatilizes  and  oxidizes  on  charcoal,  forming  a 
yellow,  volatile  coating. 

Boracic  Acid  colors  the  blowpipe  flame  an  intense  yellowish 
green.  This  test  is  more  reliable  if  the  mineral  is  moistened  with 
sulphuric  acid  before  heating. 

Carbonic  Acid  is  readily  set  free  in  the  gaseous  form,  from  all 
carbonates,  by  hydrochloric  acid,  especially  if  the  mineral  be 
pulverized  or  the  acid  heated.  The  effervescence  of  the  escaping 
carbonic  acid  is  distinguished  from  that  due  to  sulphuretted  hydrogen 
by  the  offensive  odor  of  the  latter  gas. 

Chlorine  is  most  conveniently  detected  by  adding  the  mineral  to 
a  salt  of  phosphorus  bead  which  has  been  saturated  with  copper 
oxide,  and  observing  the  intense  blue  color  which  is  imparted  to  the 
blowpipe  flame. 

Chromium  is  recognized  by  the  emerald-green  color  which  its 
oxide  imparts  to  the  borax  bead. 

Cobalt  is  most  readily  detected  by  the  cobalt-blue  color  which  its 
oxides  impart  to  the  borax  bead.  The  compounds  with'  arsenic, 
sulphur,  etc.,  should  be  carefully  roasted  (oxidized)  on  charcoal 
before  being  added  to  the  bead. 

Copper  and  its  compounds  impart  a  green  color  to  the  flame  and 
to  the  borax  and  salt  of  phosphorus  beads.  In  most  cases  the  flame 
coloration  will  be  blue  if  the  mineral  be  first  moistened  with  hydro- 
chloric acid.  Copper  can  be  reduced  from  nearly  all  of  its  ores  by 
fusion  with  soda  on  charcoal. 

Fluorine  is  recognized  in  most  of  its  compounds  by  heating  the 
mineral  in  the  closed  tube  with  potassium  bisulphate  and  pulverized 
glass.  Fluorhydric  acid  is  set  free,  which  etches  the  glass  in  the 
bottom  of  the  tube,  and  a  white  sublimate  of  silicon  fluoride  is 
formed  in  the  upper  part  of  the  tube. 

Iron  may  be  recognized  by  the  yellow  and  brown  colors  which  its 
oxides  impart  to  the  borax  bead ;  and  by  the  fact  that  nearly  all  the 
compounds  of  iron  become  magnetic  when  heated,  especially  if 
heated  on  cnarcoal  with  soda. 

Lead  is  reduced  to  the  metallic  state  with  soda,  and  forms  a 
volatile  yellow  coating  of  lead  oxide  on  the  charcoal. 

Lime  colors  the  blowpipe  flame  yellowish  red;  and  many 
compounds  of  lime  give  an  alkaline  reaction  after  heating. 


Lithia  usually  colors  the  flame  bright  purplish  red. 

Magnesia  is  recognized  in  many  of  its  compounds  by  the  pink 
color  which  they  assume  when  moistened  with  cobalt  solution  and 
strongly  ignited. 

Manganese  is  recognized  in  all  of  its  compounds  by  the  highly 
characteristic  colors  which  it  imparts  to  the  fluxes.  With  borax  it 
forms  a  clear  bead  of  a  deep  amethystine  red  or  violet-red  color ; 
while  fusion  with  soda  (or,  if  necessary,  with  soda  and  nitre)  yields 
an  opaque,  bright  green  mass. 

Mercury  always  yields  a  sublimate  of  metallic  mercury  when  any 
of  its  compounds  are  heated  in  a  closed  tube  with  soda.  This 
sublimate  consists  of  minute,  liquid  drops. 

Phosphoric  Acid  may  usually  be  recognized  by  the  green  color 
which  phosphates  impart  to  the  flame,  especially  if  previously  mois- 
tened with  sulphuric  acid.  Or  the  pulverized  mineral  may  be  fused 
in  the  closed  tube  with  a  bit  of  magnesium  wire,  and  a  drop  of  water 
added  to  the  fused  mass  when  cold,  evolving  phosphuretted  hydrogen, 
which  is  recognized  by  its  disagreeable  odor. 

Potassa  may  often  be  recognized  by  the  violet  color  which  it 
imparts  to  the  flame.  This  color  may  be  masked  by  that  due  to 
soda,  lithia,  etc. ;  but  it  may  then  be  detected  by  observing  the  flame 
through  cobalt-blue  glass,  which  quenches  the  other  colors,  but 
deepens  the  violet  of  potassa  to  purple. 

Silica  effervesces  with  soda  on  platinum  wire,  forming  a  clear 
glass,  if  the  soda  be  not  in  excess.  Most  of  the  silicates  are  decom- 
posed by  salt  of  phosphorus,  leaving  a  cloudy  skeleton  of  silica 
floating  in  the  bead.  Many  hydrous  and  basic  silicates  are  decom- 
posed by  strong  hydrochloric  acid,  leaving  the  silica  in  the  form  of  a 
stiff  jelly,  or  a  floculent  powder. 

Silver  is  easily  reduced  to  the  metallic  state  with  soda  on  charcoal, 
and  forms  a  brown  coating  of  silver  oxide. 

Soda  is  easily  recognized  by  the  intense  yellow  color  which  it 
imparts  to  the  flame. 

Strontia  is  known  by  its  crimson  flame.  The  color  is  more 
intense  when  the  mineral  is  moistened  with  chlorhydric  acid. 

Sulphur,  as  it  occurs  in  sulphides,  may  be  recognized  in  many 
ways.  Bisulphides,  or  those  containing  the  largest  proportion  of 
sulphur,  yield  sublimates  of  sulphur  in  the  closed  tube.  All 
sulphides  redden  moistened  blue  litmus  paper  in  the  open  tube.  If 
any  culphide  is  fused  with  soda  in  the  closed  tube  and  the  fused 
mass  transferred  to  a  bright  silver  coin  and  moistened  with  water,  a 
dark  brown  stain  of  silver  sulphide  is  left  on  the  coin.  This  test  will 
also  prove  the  presence  of  sulphur  in  any  sulphate,  if  a  little  pul- 
verized charcoal  is  added  to  the  mixture  in  the  closed  tube  before 
fusion,  or  the  fusion  is  made  on  charcoal.  All  sulphides  effervesce 
with  hot  hydrochloric  acid,  evolving  sulphuretted  hydrogen,  which  is 
recognized  by  its  odor. 

Tin  is  reduced  to  the  metallic  state  with  soda  on  charcoal. 

Water  may  be  expelled  from  nearly  all  hydrous  minerals  by 
heating  in  the  closed  tube,  the  vapor  or  steam  condensing  in  the 
upper  part  of  the  tube  and  wetting  the  glass. 


2O 


Zinc  is  reduced  with  soda  on  charcoal,  but  the  metal  immediately 
oxidizes,  forming  a  coating  on  the  coal  which  is  yellow  when  hot  and 
white  when  cold.  The  white  and  gray  compounds  of  zinc  assume  a 
green  color  when  moistened  with  cobalt  solution  and  strongly  ignited. 


List  of  Apparatus  and  Reagents. 

Blowpipe.  —  The  simple  and  inexpensive  brass  blowpipe  used 
by  jewellers  answers  very  well  for  all  the  tests  described  in  these 
tables;  although  the  chemical  blowpipe,  with  a  platinum  jet,  a  mouth- 
piece and  a  chamber  for  condensing  the  moisture  of  the  breath,  is, 
of  course,  rather  more  satisfactory  in  operation  and  more  durable. 

Fuel  and  Lamp.  —  The  most  satisfactory  source  of  heat  for 
blowpipe  and  chemical  experiments  is  the  Bunsen  gas-burner ;  the 
aperture  for  the  admission  of  air  at  the  bottom  of  the  burner  being 
closed  by  a  sliding  tube  when  the  blowpipe  is  used,  and  left  open 
when  it  is  desired  to  use  the  direct  heat  of  the  flame.  When  gas  is 
not  available,  a  small  alcohol  lamp  is  recommended  as  most  generally 
useful ;  although  for  use  with  the  blowpipe  alone  a  common  oil  lamp 
(olive  oil  is  best)  or  stearine  candle  will  answer  in  most  cases.  The 
blowpipe  enables  us  to  control  not  only  the  direction  but  the  quality 
of  the  flame.  The  reducing  flame  (R.  F.)  is  produced  by  holding 
the  jet  of  the  blowpipe  outside  of  the  flame  and  deflecting  the  entire 
flame  by  a  gentle  blast  without  essentially  changing  its  character. 
The  reducing  flame  should  be  used  whenever  it  is  desired  to  reduce 
to  the  metallic  state,  or  partially  deoxidize,  metallic  oxides.  The 
oxidizing  flame  (O.  F.)  is  obtained  by  introducing  the  jet  into  the 
flame  and  blowing  more  strongly,  the  deflected  flame  forming  a 
slender  blue  cone.  This  is  the  flame  usually  employed,  especially 
for  oxidizing  or  roasting  minerals,  forming  coatings  on  charcoal,  and 
whenever  a  high  temperature  is  desired,  as  in  testing  the  fusibility 
and  flame-coloration  of  minerals. 

Forceps. —  Common  steel  forceps  about  four  inches  long  will 
answer  in  most  cases  ;  although  platinum-pointed  forceps  are  very 
much  better,  if  not  essential,  in  testing  fusibility  and  flame-coloration. 

Platinum  Wire. —  A  piece  about  three  inches  long  of  moderately 
stout  wire  is  the  best.  Before  using,  a  circular  loop  one-tenth  of  an 
inch  in  diameter  should  be  formed  on  the  end  of  it. 

Glass  Tubes. —  These  should  be  of  hard  glass,  one-eighth  to 
one-fourth  inch  in  diameter,  and  three  to  four  inches  long.  The 
open  tubes  are  open  at  both  ends,  and  are  formed  by  simply  cutting 
the  tubing  with  a  file  into  pieces  of  the  proper  length.  The  closed 
tubes  are  closed  at  one  end,  and  are  formed  by  heating  pieces  seven 
or  eight  inches  long  in  the  middle  until  the  glass  is  soft  enough  to 
be  drawn  apart. 

Charcoal.— This  important  support  should  be  made  from  soft 
wood  and  thoroughly  burned,  so  as  not  to  crack  or  snap  when  heated. 


21 

Rectangular  pieces  four  to  eight  inches  long  and  two  inches  wide  are 
the  most  convenient. 

Agate  Mortar. — This  instrument  is  very  useful  in  reducing  min- 
erals to  a  fine  powder,  especially  for  treatment  with  acids ;  but  it  is 
unfortunately  somewhat  expensive. 

Hammer,  Anvil  and  Ring. — These  are  employed  to  break  and 
pulverize  fragments  of  minerals,  and  answer  in  most  cases  as  a  sub- 
stitute for  the  agate  mortar. 

File. — A  small  three-cornered  file  is  useful  for  cutting  glass  tub- 
ing. A  notch  is  made  with  the  file  in  one  side  of  the  tube,  which 
is  then  gently  bent  and  pulled  apart,  the  nails  of  the  two  thumbs 
being  brought  together  opposite  the  notch. 

Magnet. — A  small  magnet  aids  in  the  recognition  of  magnetic 
minerals. 

Lens. — A  pocket  lens  or  magnifying  glass  is  useful  in  many 
ways. 

Test-tubes. — Small  test-tubes  of  hard  glass  are  needed  for  treat- 
ing minerals  with  acids. 

Soda. — (Carbonate  of  Sodium).     Borax   (Biborate  of  Sodium). 

Salt  of  Phosphorus.   (Phosphate  of  Sodium  and  Ammonium). 
Oxide  of  Copper. — Cobalt  Solution  (Nitrate  of  Cobalt). 

Hydrochloric,  Sulphuric  and  Nitric  Acids. 

Litmus  Paper. — The  blue  paper  may  be  reddened  by  moisten- 
ing it  and  holding  it  over  the  open  mouth  of  the  acid  bottle. 

It  is  a  decided  advantage  to  beginners  in  determinative  mineralogy 
to  commence  with  species  affording  an  easy  and  natural  introduction 
to  the  use  of  the  Tables ;  and  the  following  list  of  fifty  of  the  more 
common  minerals  has  been  selected  with  special  reference  to  their 
value  for  this  use. 


Apatite.  Cuprite.  Orthoclase. 

Arsenopyrite.  Dolomite.  Pyrite. 

Barite.  Fluorite.  Pyrolusite. 

Beryl.  Galenite.  Pyrrhotite. 

Calcite.  Garnet.  Quartz. 

Celestite.  Graphite.  Rhodonite. 

Chalcedony.  Gypsum.  Siderite. 

Chalcocite.  Halite.  Sphalerite. 

Chalcopyrite.  Hematite.  Spodumene. 

Chlorite.  Hornblende,  Stibnite. 

Chromite.  Lepidolite.  Stilbite. 

Chrysotile.  Limonite.  Sulphur. 

Cinnabar.  Magnetite.  Talc. 

Copal.  Malachite.  Willemite. 

Copper.  Muscovite.  Zincite. 

Corundum.  Natrolite.  Zircon. 

Cryolite.  Obsidian. 


HOW    TO    USE    THE    TABLES. 


The  plan  of  these  Tables,  and  the  method  of  using  them  in  deter- 
mining minerals,  have  been  explained  incidentally  in  the  Introduction ; 
but  a  more  connected  statement  will  probably  be  useful  to  many 
students.  Minerals  are  divided  at  the  outset  into  two  great  classes, 
metallic  and  non- metallic.  Each  class  comprises  five  subclasses,  the 
metallic  subclasses  being  distinguished  according  to  the  colors  of  the 
minerals,  and  the  non-metallic  subclasses  according  to  the  streaks,  or 
colors  of  the  minerals  when  finely  pulverized.  The  species  in  each 
subclass  are  further  distinguished,  according  to  hardness,  as  very 
soft,  soft,  hard,  very  hard  and,  in  the  fifth  non-metallic  subclass, 
adamantine.  We  thus,  by  (i)  the  lustre,  (2)  the  color  or  streak,  and 
(3)  the  hardness,  of  minerals,  divide  them  into  forty-one  sections,  as 
shown  in  the  general  classification  on  page  25.  This  synopsis  of 
the  Tables  also  obviates  the  necessity  of  continually  turning  the 
pages,  as  it  enables  us  to  turn  at  once  to  the  section  of  the  Tables 
where  the  mineral  in  hand  is  described. 

In  the  analytical  key  on  the  left  margin  of  each  table  these 
sections  are  subdivided  in  accordance  with  other  and  various 
properties,  until  we  come  to  the  individual  species,  or  groups  of  two 
or  three  species  only,  in  the  next  column  to  the  right.  While  in  the 
succeeding  columns  we  find,  besides  the  composition,  a  concise 
physical  description  of  each  species,  by  which  it  may  be  more  care- 
fully distinguished  from  those  most  closely  resembling  it,  and  the 
identification  verified  ;  and,  finally,  the  broad  column  on  the  right 
margin  contains  a  brief  statement  of  the  chemical  tests,  which  are 
our  last  resort,  to  be  tried  only  when  the  determination  is  not  other- 
wise satisfactory. 

To  make  the  method  of  using  the  Tables  still  clearer,  a  single 
example  in  each  of  the  two  main  classes  is  appended. 


Galenite. 

Turning  to  the  general  classification  on  page  25,  we  observe  first 
that  it  is  metallic,  and  take  the  left  column ;  next  that  it  is  not  red, 
brown,  yellow  or  black,  but  gray,  belonging  in  the  fourth  subclass. 
Then,  trying  the  hardness  with  steel,  find  that  it  cuts  easily  and  is 
soft;  or  the  hardness  may  be  more  definitely  determined  by  means 
of  the  polished  surfaces  described  on  page  9,  since  we  should  find 
that  the  galenite  scratches  biotite  but  does  not  scratch  fluorite.  We 
turn  now  to  page  42  for  the  detailed  analysis  of  this  section. 


23 

Taking,  strictly  in  the  order  in  which  they  are  given,  the  general 
characters  in  the  third  column,  we  find  that  our  mineral  is  not 
malleable  or  sectile,  like  argentite  ;  that  it  is  not  yellowish,  like 
pyrrhotite;  that  it  is  not  white  on  a  fresh  fracture,  like  arsenic, 
antimony,  and  bismuth  ;  nor  light  gray,  like  stibnite  and  polydymite. 
But  it  does  agree  with  the  next  general  character  —  color  dark  lead- 
gray.  We  note  that  the  specimen  is  very  heavy  for  its  size ;  and  on 
trial  with  the  specific  gravity  balance  find  that  the  specific  gravity  (G.) 
is  above  7.  This  brings  us  to  galenite;  and  on  comparing  our  speci- 
men with  the  physical  description  of  this  species  to  the  right,  the 
determination  is  confirmed  by  the  close  agreement,  the  most  dis- 
tinctive characters  in  this  instance  being  the  dark  streak  and  cubic 
form  and  cleavage.  If,  however,  the  specimen  is  of  an  impure 
or  doubtful  character,  the  comfirmatory  chemical  test — fusion  on 
charcoal — -will  show  that  it  contains  lead  and  sulphur  and  thus 
agrees  in  composition  with  galenite.  It  is  an  excellent  plan,  even 
when  the  determination  appears  to  be  entirely  satisfactory,  to  make 
assurance  doubly  sure  by  glancing  over  the  remaining  general  char- 
acters in  that  particular  section.  Thus,  continuing  down  the  third 
column  on  page  42,  we  find  that  our  mineral  is  excluded  from  the 
next  two  general  characters  by  its  high  specific  gravity ;  from  the 
third  by  its  color  ;  and  from  the  fourth  and  last  by  both  color  and 
weight.  Here,  at  the  end  of  the  section  we  find  a  reference  by 
numbers  to  several  species  in  the  Supplementary  Tables,  and  we 
can  strengthen  the  determination  still  more,  on  the  chance  that  the 
mineral  in  hand  may  be  something  rare,  by  comparing  our  specimen 
with  each  of  these  species.  This  is  readily  done ;  and,  finding  that 
it  does  not  agree  with  either  of  them,  we  may  safely  label  it  galenite, 
since  there  is  now  only  one  chance  in  thousands  that  it  is  anything 
else. 

Leucite. 

We  find  that  this  specimen  is  without  metallic  luster,  has  a  white 
or  gray  streak  (this  is  the  streak  of  all  non-metallic  minerals 
of  white  or  gray  color,  and  many  others),  and  is  hard  (scratches 
fluorite  readily,  but  does  not  scratch  orthoclase).  This  refers  us 
to  page  72,  where  we  quickly  note  that  it  is  not  micaceous,  fibrous, 
or  columnar;  and,  passing  to  page  74,  we  next  weigh  the  specimen 
and  find  that  its  G.  is  below  3.8,  and  also  below  2.8.  Therefore, 
we  pass  page  76  to  page  78,  and  note  that  it  is  not  deep  blue,  and 
find  on  trial  that  it  does  not  yield  water  in  the  closed  tube;  and 
does  not  gelatinize  when  the  fine  power  is  boiled  with  HC1  in  a  test 
tube.  This  brings  us  to  a  group  of  three  species ;  and  our  mineral 
is  readily  identified  as  leucite  by  its  lower  G.  and  characteristic 
isometric  form. 

The  number  in  parenthesis,  following  the  name  of  each  species, 
refers  to  the  synopsis  of  the  classification  of  minerals  on  pages  98 
to  100,  where  we  learn  at  a  glance  the  general  relations  of  galenite 
and  leucite  to  the  rest  of  the  mineral  kingdom. 


24 

In  all  cases  where  the  meaning  of  the  Tables  is  not  clear,  the 
student  should  refer  to  the  section  of  the  Introduction  where  the 
property  or  test  is  explained;  and  attention  is  especially  directed 
to  the  means  for  the  more  accurate  determination  of  the  streak 
H.  and  G.,  as  explained  on  pages  9  and  10. 

In  conclusion,  it  may  fairly  be  said  that  the  golden  rule  in 
determinative  mineralogy  is  to  follow  the  order  of  the  tables,  and  not 
skip  about,  or  guess  at  the  names  or  relations  of  minerals. 


Those  desiring  to  obtain  mineral  specimens  suitable  for  deter- 
minative work,  the  abbreviated  scale  of  hardness  (biotite,  fluorite, 
feldspar,  and  quartz)  described  on  page  9,  or  any  of  the  apparatus 
required  for  use  with  the  Tables,  are  referred  to  the  advertisement 
at  the  end  of  the  book. 

Mr.  Thomas  A.  Upham,  17  Harvard  Place,  Boston,  furnishes 
excellent  blowpipe  apparatus,  singly  or  in  sets ;  and  orders  for  the 
specific  gravity  balance  described  on  page  10  should  be  sent  to  him. 
Price  :  $4.50. 


GENERAL  CLASSIFICATION. 


A.  WITH  METALLIC  LUSTER. 

L     Color  red  or  brown. 

1.  Very  soft 

2.  Soft      . 

3.  Hard      .         .         . 

4.  Very  hard 

II.  Color  yellow. 

1 .  Very  soft 

2.  Soft    .         .         . 

3.  Hard      .         .   .      . 

4.  Very  hard 

III.  Color  black. 

1.  Very  soft 

2.  Soft    . 

3.  Hard     . 

4.  Very  hard 

IV.  Color  gray. 

1.  Very  soft 

2.  Soft    . 

3.  Hard      . 

4.  Very  hard  . 

V.  Color  white. 

1.  Very  soft 

2.  Soft    . 

3.  Hard      . 

4.  Very  hard  . 


>TER. 

B.  WITHOUT  METALLIC  L 

Page. 

I.     Streak  red  or  brown, 

26 
26 

i.     Very  soft 

2.       Soft     .... 

.    '      28 
28 

3.     Hard      . 
4.     Very  hard 

II.  Streak  yellow. 

3° 
3° 
3° 
32 

i.     Very  soft        ,    . 
2.     Soft    .         .,       ;. 
3.     Hard      . 
4.     Very  Hard 

III.     Streak  black. 

32 
34 
.         36 

38 

i.     Very  soft    . 
2.     Soft    .... 
3.     Hard     . 
4.     Very  hard 

IV.     Streak  green  or  blue. 

40 
42 

44 
46 

i.     Very  soft 

2.       Soft     .... 

3.     Hard      . 
4.     Very  hard 

V.     Streak  white  or  gray. 

.          46 
48 
48 
48 

i.     Very  soft 

2.       Soft      .... 

3.     Hard     . 
4.     Very  hard 
5.     Adamantine    . 

Page. 

5° 
5° 
52 
54 


56 
56 
56 
58 


58 
58 
58 
58 


60 
60 
60 
60 


62 
66 
72 
80 
88 


26 


A.     MINERALS     WITH 


Analytical  Key. 

Species. 

Composition 

Luster. 

Color. 

Streak. 

Vlicaceous. 
^olise 
elastic. 

Phlogopite  (75). 

(KMgAl)2 
Si04. 

Dearly  to 
submetallic. 

Yellowish 
brown  to 
Brownish 
red. 

White. 

Streak  red. 
Ochery. 

Turgite  (Red 
Ocher)   (28). 

2Fe203+ 
H2O. 

Dull. 

Red. 

Red. 

i 

Streak  red. 

Realgar  (13). 

AsS. 

Resinous. 

Aurora-red 
to  orange- 

Orange-red 
to 

*•»•  J  4- 

yellow. 

aurora-red. 

£ 

Streak  red. 

Proustite  (16). 

Ag3AsS3. 

Adamantine 
to   dull. 

Scarlet- 
vermilion. 

Scarlet- 
vermilion. 

0.5-6, 
when  pure. 

Pyrargyrite(i6). 
Compare  S.  T.  15.] 

Ag3SbS3. 

Adamantine 
to   dull. 

Black,   red 
by  trans- 
mitted light. 

Purplish 
red. 

Streak 

Cochineal- 

bright  red. 
G.  about  8, 

Cinnabar/  (9)  . 

HgS. 

Adamantine 
to   dull. 

red  to 
Brownish 

Scarlet. 

when  pure. 

/ 

red. 

I 

Micaceous. 
Foliae 
elastic. 

Phlogopite  (75). 

(KMgAl)2 
SiO4. 

Pearly  to 
submetallic. 

Yellowish 
brown  to 
brownish 
red. 

White. 

fe 

Streak  red. 
Malleable. 

Copper  (2V. 

Cu. 

Metallic. 

Copper-red. 

Copper-red. 

v 

V 

*. 

Streak 

Cochineal- 

,2 

a 

bright  red. 
G.  about  8, 

Cinnabar  /9). 

HgS. 

Adamantine 
to   dull. 

red  to 
brownish  . 

Scarlet. 

when  pure. 

red 

Proustite  (16). 

Ag3AsS3. 

Adamantine 
to   dull 

Scarlet- 
vermilion 

Scarlet- 
vermilion. 

i 

Streak  red. 
G.  5-6, 
when  pure. 

Pyrargyrite(i6). 

AgsSbSg. 

Adamantine 
to   dull. 

Black,  red 
by  trans- 
mitted light 

Purplish 
red. 

Cuprite  (26). 

Cu20. 

Adamantine 
to   dull 

Red  to 
brown 

Brownish 
red. 

V 

Streak 
orange. 

Zincite  (21). 

ZnO. 

Sub- 
adamantine 

Red 
to  brown 

Orange. 

G.  5-6. 

Streak  red, 

Turgite  (2^). 

2Fe203+ 
H20 

Submetallic 
to  silky 
and  dull 

Reddish 
black  to  red 

Red. 

brown  or 

yellow. 

Light 

•  3-4-5 

Sphalerite  (8). 

ZnS. 

Resinous. 

Brown. 

brown  to 

Compare  Hematite. 

pale   yellow. 

METALLIC     LUSTER. 


27 


H. 

Tenacity. 

G. 

Form. 

Cleavage. 

Other 
Properties. 

Confirmatory  Chemical  Tests. 

2-5- 
3- 

Elastic  and 
sectile. 

2.8 

V.  Foliated. 

Basal, 
perfect. 

Transparent 
to  opaque. 

B.  B.  infusible;  yields  a  little  water 
in  closed  tube;    decomposed   by 
strong  sulphuric  acid. 

B.  B.    infusible;    yields    water    in 

1-2. 

Earthy. 

3- 

Compact. 

Earthy. 

Opaque. 

closed  tube;   becomes  black  and 

3-5 

magnetic  on  charcoal  in  R.  F. 

'•5- 

2. 

Brittle. 

3-5 

V.     Also 
massive. 

Clinopina- 
coidal  and 
basal. 

Transparent 
to 
translucent. 

B.  B.  on  charcoal,  volatile  and  com- 
bustible, burning  with  a  blue  flame 
and  arsenical  odor;  red  sublimate 
in  closed  tube. 

2- 

2-5 

Brittle. 

5.6 

III.  Also 
massive. 

Conchoidal. 

Translucent 
to 
transparent. 

B.  B.  on  charcoal,  fuses  easily  (i), 
and  emits  odors  of  S  and   As; 
with  soda  in  R.  F.  gives  globule  of 
Ag;  white  sublimate  in  open  tube. 

B.B.  on  charcoal,  fuseseasilv(i)with 

2-5 

Brittle. 

5-7- 
S-9 

III.     Also 
massive. 

Conchoidal. 

Opaque  to 
translucent. 

spirting,  giving  white  coating;  with 
soda  in  R.  F.  gives  Ag;  red  subli- 

mate in  closed,  white  in  open  tube. 

2- 
2-5 

Brittle  to 
sectile. 

8- 

8.2 

III.   Usually 
massive. 

Uneven. 

Usually 
opaque. 

B.B.  volatile;  with  soda  in  closed 
tube  yields  sublimate  of  mercury. 

K.  . 

2-5- 
3- 

Elastic  and 
sectile. 

2.8 

V.  Foliated. 

Basal, 
perfect. 

Transparent 
to  opaque. 

B.  B.  infusible;  yields  a  little  water 
in  closed  tube;     decomposed  by 
strong  sulphuric  acid. 

2-5- 
3- 

Malleable. 

8.8- 
8-9 

I.  Also  mas- 
sive and 
arborescent. 

None. 

Opaque. 

B.  B.  fuses   very   easily  (78o°C.); 
green    solution    with  nitric  acid, 
which  becomes  blue  with  ammo- 

nia. 

2- 
2-5 

Brittle  to 
sectile. 

8- 

8.2 

III.   Usually 
massive. 

Uneven. 

Usually 
opaque. 

B.  B.  volatile;  with  soda  in  closed 
tube  yields  sublimate  of  mercury. 

B.  B.  on  charcoal,  fuses  easily  (i), 

2- 
2-5 

Brittle. 

5.6 

III.  Also 
massive. 

Conchoidal. 

Translucent 
to  opaque. 

and  emits  odors   of  S  and    As; 
with  soda  in  R.  F.  gives  globule  of 

Ag;  white  sublimate  in  open  tube. 

B.B.  on  charcoal,  fuses  easily  (i)  with 

2-5 

Brittle. 

5-7- 
5-9 

III.  Also 
massive. 

Conchoidal. 

Translucent 
to  opaque. 

spirting.giving  white  coating;  with 
soda  in  R.  F.  gives  Ag;  red  subli- 

mate in  closed,  white  in  open  tube. 

3-5- 
4- 

Brittle. 

S-9- 
6.1 

I.  Also  cap- 
illary  and 
massive. 

Octahedral. 

Translucent 
to  opaque. 

B.  B.    colors  flame  green  and  fuses 
readily,  yielding  metallic  copper 
on  charcoal. 

4- 
4-5 

Brittle. 

5-4- 
5-7 

III.  Also 
massive. 

Basal, 
perfect. 

Usually 
opaque. 

B.  B.  infusible;   soluble    in  acids; 
with  soda  on  charcoal  gives  coat- 
ing of  zinc  oxide. 

3-4- 

Brittle  to 
earthy. 

3-5- 
4- 

Massive, 
botryoidal, 
fibrous,  etc. 

Uneven, 
splintery, 
etc. 

Opaque. 

B.    B.   infusible;     yields    water    in 
closed  tube;   becomes  black  and 
magnetic  on  charcoal  in  R.  F. 

B.    B.    infusible;   reactions    for  sul- 

•J e 

Brittle 

S-9- 

I.     Also 

Dodecahe- 

Transparent 

phur;     zinc    oxide    coating   with 

4.2 

massive. 

dral,  perfect. 

to  opaque. 

soda  on  charcoal;   effervesces  in 

hot  acid,  evolving  H2S. 

28 


A.     MINERALS     WITH 


Analytical  Key. 

Species. 

Composition 

Luster. 

Color. 

Streak. 

Reddish 

Dark 

i  •« 

i    ^ 

Streak 
black. 

Pyrrhotite  (9). 

Fe7S8. 

Metallic. 

bronze- 
yellow. 

grayish 
black. 

5Q  "4S 

G.  4-5-5-5 

,•3 

Compare 
tarnish. 

Bornite  (6). 

\y' 

Cu3FeS3. 

Metallic. 

Brownish 
copper-red. 

Dark 
grayish 
black; 

Streak 

Niccolite  (9). 

NiAs. 

Metallic. 

Pale 
copper-red. 

Dark 
brownish 
black. 

black. 

Compare  G. 

Bronze- 

Dark 

Pyrrhotite  (9). 

Fe7S8. 

Metallic. 

yellow  to 

grayish 

copper-red. 

black. 

Streak  light 

Light  brown 

brown  to 

Sphalerite  (8). 

ZnS. 

Resinous. 

Brown. 

to  pale 

pale  yellow. 

yellow. 

Streak 

| 

orange. 
G.  5-4-5-7 

Zincite  (21). 

ZnO. 

Sub- 
adamantine. 

Red  to 
orange. 

Orange. 

8 

1 

Streak 

Gothite  {zg). 

!  +H20. 

Adamantine 
to  dull. 

Brown. 

Yellow. 

deep 

I 

•2 

4 

yellow. 
Compare  G. 

Limonite  (30). 

2Fe2O3 
+3H20. 

Submetallic 
to  silky 
and  dull. 

Brown. 

Yellow. 

& 

• 

Strreak 

Cochineal- 

1 

bright  red. 
G.  about  S, 

Cinnabar  (9). 

HgS. 

Adamantine 
to  dull. 

red  to 
brownis.h 

Scarlet. 

when  pure. 

V 

red. 

a 

j. 

Cuprite  f£o). 

Cu2O. 

Adamantine 
to  dull. 

Red  to 
brown. 

Brownish 
red. 

Streak  red. 

v 

Pyrargyrite(i6). 

AgsSbS8. 

Adamantine 
to  dull. 

Black,  red 
by  transmit- 
ted light. 

Purplish 
red. 

Streak  red. 

Turgite  (28). 

2Fe2O3 
+H20. 

Submetallic 
to  silky 
and  dull. 

Reddish 
black  to 
red. 

Red. 

G.  below  5.5 

Hematite  (2$). 
[CompJkr^  S.  T.  ^.\ 

Fe203. 

Metallic 
to  dull. 

Black  to  red. 

Red. 

Brown  to 

1 

G.  nearly  7. 

Cassiterite  (26). 

SnO2. 

Adamantine. 

reddish 
brown. 

Gray  to 
light  brown. 

1 

Reddish 

Gray   to 

. 

G.  4.2 

Rutile   (26}. 

Ti02. 

Adamantine. 

brown 

yellowish 

* 

Compare  Brookite. 

to   red. 

brown. 

METALLIC     LUSTER. 


29 


H. 

3-5- 
4- 

Tenacity. 

G. 

Form. 

Cleavage. 

Other 
Properties. 

Confirmatory  Chemical  Tests. 

Brittle. 

4-6 

III.  Usually 
massive. 

Uneven. 

3paque. 
Dull  brown 
tarnish. 

B.  B.  fuses  easily  to  a  black,  mag- 
netic mass;  usually  slightly  mag- 
netic before  fusion. 

i 
3- 

Brittle. 

4-5- 

5-5 

I.     Usually 
massive. 

Octahedral, 
in  traces. 

Opaque. 
Blue  and 
green 
tarnish. 

jives  reactions  for  copper;  B.  B. 
fuses  easily  to  a  black,  magnetic 
globule. 

5~ 
5-5 

Brittle. 

7-3- 
7-7 

III.   Usually 
massive. 

Uneven. 

Opaque. 

B.  B.  on  charcoal  fuses  easily,  yield- 
ing arsenical  fumes  and  coating 
and  a  magnetic  globule. 

4- 
4-5 

Brittle. 

4.6 

III.   Usually 
massive. 

Uneven. 

Opaque. 

B.  B.  fuses  easily  to  a  black,  mag- 
netic mass;  usually  slightly  mag- 
netic before  fusion. 

4- 

4-5 

Brittle. 

3-9- 
4.2 

I.  Usually 
massive. 

Dodecahe- 
dral,  perfect. 

Transparent 
to  opaque. 

B.  B.  infusible;  reactions  for  sul- 
phur; coating  of  zinc  oxide  with 
soda  on  charcoal;  effervesces  in 
hot  acid,  evolving  H2S. 

Brittle. 

5-4- 
5-7 

III.  Also 
massive. 

Basal, 
perfect. 

Usually 
opaque. 

B.  B.  infusible;  soluble  in  acids; 
with  soda  on  charcoal  gives  coat- 
ing of  zinc  oxide. 

5- 
5-5 

Brittle. 

4- 
4-4 

IV.  Colum- 
nar,   fibrous 
or 
botryoidal. 

Prismatic, 
perfect. 

Opaque. 

B.  B.  infusible;  water  in  closed 
tube;  becomes  black  and  mag- 
netic on  charcoal  in  R.  F.;  sol- 
uble in  HC1. 

5- 
5-5 

2-5 

4- 

Brittle. 

3-6- 
4- 

Compact, 
botryoidal, 
fibrous,  etc. 

Uneven, 
splintery, 
«tc. 

Opaque. 

Like  gothite. 

Brittle  to 
sectile. 

Brittle. 

8. 

III.  Usually 
massive. 

Uneven. 

Usually 
opaque. 

B.  B.  volatile;  with  soda  in  closed 
tube  yields  sublimate  of  mercury. 

5-9- 
6.1 

I.  Also 
capillary  and 
massive. 

Octahedral. 

Translucent 
to  opaque. 

B.  B.  colors  flame  green  and  fuses 
readily  ;  yields  metallic  copper  on 
charcoal. 

2-5 

Brittle. 

5-7- 
5-9 

III.  Also 
massive. 

Conchoidal. 

Translucent 
to  opaque. 

B.B.  on  charcoal,  fuses  easily(i)with 
spirting  and  white  coating;  with 
soda  in  R.  F.  gives  Ag  ;  red  subli- 
mate in  closed,  white  in  open  tube. 

4-5 

Brittle. 

3-5- 
4-5 

Massive, 
botryoidal, 
fibrous,  etc. 

Uneven, 
splintery, 
etc. 

Opaque. 

B.  B.  infusible;  yields  water  in 
closed  tube;  becomes  black  and 
magnetic  on  charcoal  in  R.  F.; 
soluble  in  HC1. 

4-5- 
6-7 

Brittle. 

4.2- 
4.9 

Massive, 
botryoidal, 
fibrous,    etc. 

Uneven, 
splintery, 
etc. 

Opaque. 

B.  B.  infusible;  no  water  in  closed 
tube;  becomes  black  and  mag- 
netic on  charcoal  in  R.  F.  ;  sol- 
uble in  HC. 

Brittle. 

6.8- 
7-i 

II.  Also 
massive,  bot- 
ryoidal, etc. 

Prismatic, 
indistinct 

Nearly 
opaque. 

B.  B.  infusible;  insoluble;  with 
soda  on  charcoal  reduced  to  me- 
tallic tin. 

6- 
6.5 

Brittle. 

4.2 

II.  Also 
massive. 

Prismatic, 
distinct 

Nearly 
opaque 

B.  B.  infusible;   insoluble. 

A.     MINERALS     WITH 


Analytical  Key. 

Species. 

Composition 

Luster. 

Color. 

Streak. 

Streak 

white. 
Micaceous. 

Phlogopite  (75). 

(KMgAl)2 
SiO4. 

Pearly  to 
submetallic. 

Yellow  to 
brown. 

White. 

Folise  elastic. 

! 

Malleable. 

Gold  (i). 

Au. 

Metallic. 

Gold-yellow. 

Gold-yellow. 

J-H 

Brittle. 

Orpiment  (14). 

As2S3. 

Pearly  to 
resinous. 

Lemon  - 
yellow. 

Lemon- 
yellow. 

Earthy. 

Limonite  (Yel- 
low Ocher)  (30). 

2Fe2O3 

Dull. 

Yellow. 

Yellow. 

Streak 
white. 
Micaceous. 

Phlogopite  (75). 

(KMgAl) 
SiO4. 

Pearly  to 
submetallic. 

Yellow  to 
brown. 

White. 

Folise  elastic. 

Malleable. 

Gold  (i). 

Au. 

Metallic. 

Gold-yellow. 

Gold-yellow. 

r2 

Streak 
orange. 

Zincite  (21). 

ZnO. 

Sub- 
adamantine. 

Red  to 
orange. 

Orange. 

§ 

i 

Streak 
yellowish 
white. 

Sphalerite  (8). 

ZnS. 

Resinous. 

Brown  to 
yellow. 

Yellowish 
white. 

fcj 

^ 

Streak    light 

Light 

Light 

bronze- 

Pentlandite  (8). 

(FeNi)S. 

Metallic. 

bronze- 

bronze- 

brown. 

yellow. 

brown. 

Streak 
black. 
Acicular 
or  fibrous. 

Millerite   (9). 

NiS. 

Metallic. 

Brass- 
yellow. 

Dark 
greenish 
black. 

Streak 
black  or 
nearly  so. 

Chalcopyrite 

(CuFe)S2. 

Metallic. 

Brass- 
yellow. 

Dark 
greenish 
black. 

Compare 

color  and 
tarnish. 

Pyrrtfotite  (9). 

Compare 
^Polydymite. 

Fe7S8. 

Metallic. 

Bronze- 
yellow. 

Dark 
grayish 
black. 

Streak 
yellowish 

Zincite  (21). 

ZnO. 

Sub- 
adamantine. 

Red  to 
orange. 

Orange. 

'sS 

white. 

1 

G.  about  4. 

Sphalerite  (8), 

ZnS. 

Resinous. 

Brown  to 
yellow. 

Yellowish 
white. 

Streak  near- 
ly black. 
G.  above  5.5 
H.  about  6. 

Arsenopyrite 

(n). 

FeAsS. 

Metallic. 

White  to 
gray. 

Dark 
grayish 
black. 

METALLIC     LUSTER. 


H.        Tenacity. 

G. 

Form. 

Cleavage.       _  Other 
Properties. 

Confirmatory  Chemical   Tests. 

Elastic  and 
sectile. 

2.8 

V.  Foliated. 

Basal,              Transparent 
perfect.!    to  opaque. 

B.    B.  infusible;  yields  a  little  wa- 
ter in  closed  tube;    decomposed 
by  strong  sulphuric  acid. 

IS.6 

I.  Usually 

B.  B.    fusible    at  3;    insoluble    in 

2.S 

Malleable. 

to 

in  grains      None.             Opaque. 

common  acids;     soluble   in  aqua 

19.3 

or  nuggets. 

regia;   does  not  tarnish. 

.        i 

B.B.  on  charcoal,  volatile  and  com- 

2. 

Sectile  to 
brittle. 

3-5 

1   1  coidal,  very 

Translucent. 

bustible,  burning  with   blue  flame 
and  arsenical  odor;   dark  yellow 

i 

sublimate  in   closed  tube. 

B.  B.    infusible;     water    in    closed 

1-2. 

Earthy.            3~ 

Earthy.           None. 

Opaque. 

tube;    becomes  black    and    mag- 
netic on  charcoal  in  R.  F.;   sol- 

uble in  HC1. 

2-5 

Elastic  and 
sectile. 

2.8 

V.   Foliated. 

Basal, 
perfect. 

Transparent 
to  opaque. 

B.  B.  infusible;   yields  a  little  wa- 
ter in  closed  tube;    decomposed 
by  strong  sulphuric  acid. 

IS.6 

I.  Usually     j 

B.  B.  fusible  at  3;  insoluble  in  com- 

2-.S 

Malleable. 

to 

in  grains 

None.              Opaque. 

mon  acids;  soluble  in  aqua  regia; 

19-3 

or  nuggets.) 

does  not  tarnish. 

4- 

Brittle. 

5-4- 
5-7 

III.  Also        Basal, 
massive.           perfect. 

Usually 
opaque. 

B.  B.   infusible;     soluble   in    acid; 
gives  coating  of  zinc  oxide  with 
soda  on  charcoal. 

3-5- 
4- 

Brittle. 

3-9- 
4.2 

I.  Usually 
massive. 

Dodecahe- 
dral,  perfect. 

Translucent 
to  opaque. 

B.  B.  infusible;     reactions   for   sul- 
phur; with  soda  on  charcoal  gives 
a  coating  of  zinc  oxide;  efferves- 

ces in  hot  acid,  evolving  H2S. 

3-5- 
4- 

Brittle. 

4.6 

I.  Massive 

and             Octahedral. 

Opaque. 

Sulphurous    fumes    in    open    tube; 
B.  B.    easily   fusible  to  magnetic 
globule;  reactions  for  nickel  with 

granular.! 

fluxes. 

3-      Brittle. 
3-5 

4.6- 
5-6 

III.  Acicular 
or  fibrous. 

Rhombo- 
hedral. 

Opaque. 

B.  B.    fuses   easily;   yields  sulphur 
fumes  ;  in  R.  F.  on  charcoal  gives 
magnetic  mass. 

3-5- 

4- 

Brittle. 

4.1- 
4-3 

II.    Usually 
massive. 

Uneven. 

Opaque. 
Iridescent 
tarnish. 

Sulphur  in  closed  tube;   B.  B.  fuses 
(2)  to  magnetic  globule  on  char- 
coal and  gives  metallic  copper  with 
soda;  green  solution  with  HNO  . 

3-5- 

Brittle. 

4-4- 

III.    Usually 

Uneven. 

Opaque. 
Dull  brown 

B.  B.    fuses  easily  to  a  black  mag- 
netic mass;  usuallv  slightly  mag- 

4* 

4-7 

tarnish. 

netic  before  fusion. 

B.  B.  infusible;    soluble   in    acid; 

4- 

Brittle. 

5-4- 

III.    Also 

Basal, 

Usually 

gives  coating  of  zinc  oxide  with 

4-5 

5-7 

massive. 

perfect. 

opaque. 

soda  on  charcoal. 

B.  B.    infusible;   reactions   for   sul- 

3-5- 
4- 

Brittle. 

3-9- 

4-2 

I.  Usually 
massive. 

Dodecahe- 
dral,  perfect. 

Translucent 
to  opaque. 

phur;  with  soda  on  charcoal  gives 
a  coating  of  zinc  oxide;  efferves- 

ces in  hot  acid,  evolving  H«S. 

i 

B.  B.  on  charcoal     fuses  at  2,  giv- 

r 

Brittle.            J~ 
6.4 

IV.  Also 
massive. 

Prismatic, 
distinct. 

Opaque. 
Tarnishes 
yellowish. 

ing  an  arsenical  coating   and    a 
magnetic   residue;   arsenic  subli- 
mate in  closed  tube. 

32 


A.     MINERALS     WITH 


Analytical  Key. 

Species. 

Composition 

Luster. 

Color. 

Streak. 

Streak 
nearly 

Marcasite  (n). 

FeS2. 

Metallic. 

Grayish 
yellow. 

Dark 
Brownish 
black. 

2 

black. 

Brownish 

"s 

G.  below  5.5 
H.  about  6. 

Pyrite  (10). 

FeS2. 

Metallic. 

Pale  brass- 
yellow. 

black  to 
greenish 

Co 

/ 

black. 

1 

^^ 

S 

1 

1, 

1 

Streak  near- 
ly black. 
G.  below  5.5 

Chalcopyrite 
\j         (10). 

(CuFe)S2. 

Metallic. 

Brass- 
yellow. 

Dark 
greenish 
black. 

a 

8*5 

ti.  about  4. 

Compare 
color  and 
tarnish. 

Pyrrhotite   (9). 

Compare 

Fe7S8. 

Metallic. 

Bronze- 
yellow. 

Dark 
grayish 
black. 

§ 

v^  Poly  dy  mite. 

§ 

^3 

Streak  near- 
ly black. 
G.  above  5.5 

Arsenopyrite 

(n). 

FeAsS. 

Metallic. 

White  to 
gray- 

Dark 
grayish 
black. 

s 

fcq 

Dark 

I 

Streak  near- 

Marcasite (n). 

FeS2. 

Metallic. 

Grayish 
yellow. 

brownish 
black, 

ly  black. 

Brownish 

G.  below  5.5 

Pyrite  (10). 

FeS2. 

Metallic. 

Pale  brass- 
yellow. 

black  to 
greenish 
black. 

Micaceous. 
Foliae 
elastic. 

Biotite  (75). 

(AlKoMg 
Fe)2Si04 

Pearly  to 
submetallic 

Black  to 
green. 

Grayish 
white. 

Iron-black 

Greasy   feel. 

Usually 
foliated. 

Graphite  (5). 

C. 

Metallic. 

to 
dark  gray 

Black. 

Folise  not 

elastic. 
Compare  G. 

Molybdenite 

(15)- 

MoS2. 

Metallic. 

Lead  gray. 

Dark 
lead-gray. 

9 

4 

Malleable 
and  sectile 

Argentite   (6). 

Ag2S. 

Metallic. 

Blackish 
lead-gray 

Blackish 
lead  -gray. 

| 

SQ 

a 

^ 

Streak 

?MnO 

g 

s 

black 
Earthy. 

Wad  (32). 

+H20. 

Dull. 

Black. 

Black. 

Iron-black 

Pyrolusite   (27). 

MnO2. 

Metallic. 

to 

Black. 

Streak 

dark  gray. 

black 

Compare  G 

• 

Stephanite  (16). 

Ag5SbS3. 

Metallic. 

Iron-black. 

Iron-black. 

Streak  red. 

Pyrargyrite(i6). 

Ag3SbS3. 

Adamantine 

Black,  red 
by  transmit- 

Purplish 
red 

[Compare   S.  T.  21]. 

ted  light. 

METALLIC     LUSTER. 


33 


H. 

Tenacity. 

G. 

Form. 

Cleavage. 

Other 
Properties. 

Confirmatory  Chemical  Tests. 

6- 
6.5 

Brittle. 

4-9 

IV.  Often 
massive  or 
globular 

Prismatic. 

Opaque. 
Decomposes 
readily. 

Sublimate  of  sulphur  in  closed  tube; 
B.  B.  on  charcoal,  fuses     easily, 
gives  off  S,  burning  with  a  blue 
flame,  leaves  a  magnetic  residue. 

I.  Cubes  anc 

6- 

6.5 

Brittle. 

4.8- 

5-2 

pyritohe- 
drons;  often 

Uneven. 

Opaque. 

Like  marcasite. 

massive 

4- 

Brittle. 

4.1- 
4-3 

11.  Usually 
massive 

Uneven. 

Opaque. 
Iridiscent 
tarnish 

Sulphur  in  closed  tube;  B.  B.  fuses 
(2)  to  a  globule  on  charcoal  and 
gives  metallic  copper  with  soda; 

green  solution  with  nitric  acid. 

4- 

4C 

Brittle. 

4.4- 
4-7 

III.  Usually 
massive 

Uneven. 

Opaque. 
Dull  brown 

B.  B.  fuses  easily  to  a  black  mag- 
netic mass;  usually  slightly  mag- 

tarnish 

netic  before  fusion. 

6. 

Brittle. 

6- 
6.4 

IV.  Also 
massive 

Prismatic, 
distinct 

Opaque. 
Yellow 
tarnish 

B.  B.  on   charcoal  fuses  at  2,  giving 
an  arsenic  coating,  and  magnetic 
residue  ;  arsenic  sublimate  in  tube. 

6- 

6.5 

Brittle. 

4-9 

IV.  Often 
massive  anc 
globular 

Prismatic. 

Opaque. 
Decomposes 
readily 

Sublimate  of  sulphur  in  closed  tube  ; 
B.  B.  on  charcoal,   fuses   easily, 
gives  off  S,  burning   with  a  blue 
flame,  leaves  a  magnetic  residue. 

I.  Cubes  anc 

6- 
6.5 

Brittle. 

4.8- 
5-2 

pyritohe- 
drons;  often 

Uneven. 

Opaque. 

Like  marcasite. 

massive 

2-5 

Elastic  and 
sectile 

2.9 

V.  Foliated 

Basal, 
perfect 

Transparent 
to  opaque 

B.  B.     infusible;      decomposed   by 
strong  sulphuric  acid. 

1-2. 

Sectile. 

2- 
2.2 

III.  Usually 
foliated 

Basal, 
perfect 

Opaque. 
Greasy  feel. 

B.  B.  infusible;  unaltered   by  acids. 

I- 

<t.,-ti'i(=> 

4-7- 

III.   Usually 

Basal, 

Opaque. 

B.    B.    infusible;   reactions    for  sul- 

i-5 

4.8 

foliated 

perfect 

Greasy  feel. 

phur  in  open  tube  and  with  soda. 

Reactions  for  sulphur  in  open  tube 

2. 

Malleable 
and  sectile 

7-3 

I.  Also 
massive 

Uneven. 

Opaque. 

and  with  soda;    B.  B.  on  charcoal 
fuses    at    1.5,      yielding   metallic 

silver. 

B.  B.    infusible;     yields    water    in 

1-2. 

Earthy. 

3-4- 

Amorphous. 

Earthy. 

Opaque. 

closed   tube;     amethystine    bead 
with  borax;  evolves  chlorine  with 

HC1. 

IV.  Usually 

B.  B.  infusible;    amethystine   bead 

2. 

Brittle. 

4-8 

columnar  or 

Prismatic. 

Opaque. 

with     borax;      evolves     chlorine 

massive. 

with  HC1. 

2. 

Brittle. 

6.25 

IV.  Usually 
massive. 

imperfect. 

Opaque. 

3.B.   on   charcoal,   fuses  easily  (i), 
giving  a  coating  of  antimony  oxide 

and,  with  soda,  a  globule  of  silver. 

2. 

Brittle. 

S-8 

III.  Also 

Conchoidal. 

Opaque 
to 

3.B.  on  charcoal,  f  uses  easily(i)  with 
spirting,  giving  white  coating;  with 

translucent. 

soda  in  R.  F.  gives  Ag;  red  subli- 
mate in  closed,  white  in  open,  tube. 

A.     MINERALS     WITH 


Analytical     Key. 

Species. 

Composition 

Luster. 

Color. 

Streak. 

Micaceous. 

Biotite  (75). 

(KFeMg 
Al)2SiO4. 

Pearly  to 
submetallic. 

Black. 

White. 

Folise 

elastic. 

Lepidomelane 

C75)- 

(KFeAl)2 
SiO4. 

Adamantine 
to  pearly. 

Black. 

Grayish 
green. 

Malleable. 

Argentite  (6).      A^2  J. 

Metallic. 

Blackish 
lead-gray. 

Blackish 
lead-gray. 

Streak  red. 

Hematite  (25). 

Fe2O3. 

Metallic. 

Black  to 
gray. 

Red. 

Pyrargyrite(i6). 

AgsSbSs. 

Adamantine 
to  dull. 

Black,  red  by 
transmitted 

Purplish 
red. 

light. 

Streak 
brown. 

Sphalerite  (8). 

ZnS. 

Submetallic. 

Black. 

Brown. 

•S 

StrCak  black   Mineral  Coal 

C,H,O,  etc. 

Submetallic. 

Black. 

Black. 

s 

G.   1-2.                                    (S^- 

U 

| 

'o4 

Streak 

V 

black. 
G.  below  5.3 

Wad  (32). 

Hap. 

Dull. 

Black. 

Brownish 
black. 

»3 

cs, 

Dull,  earthy. 

5^. 

Streak 

| 

black. 
G.  below  5.3 
Columnar. 

Manganite  (29). 
Compare  Pyrolnsite. 

Mn203+ 
H20. 

Submetallic. 

Iron-black 
to  steel-gray. 

Brownish 
black. 

*^" 

Streak 
black. 

Tetrahedrite 
\J      (16). 

Cu8Sb2S7. 

Metallic. 

Dark  gray  to 
iron-black. 

Dark  gray  to 
black. 

G.  below  5.3 

Color  usually 
dark  gray. 

Enargite  (16). 

Cu3AsS4. 

Metallic. 

Grayish  to 
iron-black. 

Dark  grayish 
black. 

Streak 

black. 

Stephanite  (16). 

Ag5SbS4. 

Metallic. 

Black. 

Black. 

G.  above  5.3 

Reactions 

for  antimony 
in  open  tube. 
Compare   G. 

Bournonite(i6). 

H 

CuPbSbS«. 

Metallic. 

Steel-gray  to 
iron-black. 

Dark  gray  to 
black. 

Streak 
black. 

Chalcbcite  (7). 

Cu2S. 

Metallic. 

Blackish 
lead-gray. 

Blackish 
lead-gray. 

G.  above  5.3 

/ 

Color  flame 
green. 

Melaconite  (22). 

NV 

CuO. 

Metallic  to 
dull. 

Black. 

Black. 

METALLIC     LUSTER. 


35 


H. 

Tenacity. 

G. 

Form. 

Cleavege. 

Other 
Properties. 

Confirmatory  Chemical  Tests. 

2-75 

Elastic  and 
sectile. 

2.9 

V.  Foliated. 

Basal, 
perfect. 

Transparent 
to 
opaque. 

B.    B.    infusible;     decomposed    by 
strong  sulphuric  acid. 

C              ,  •!             . 

3- 

brittle. 
Little 
elastic. 

3- 

V.  Foliated. 

Basal, 
perfect. 

Opaque  to 
translucent. 

B.  B.  fuses  easily  to  magnetic  glob- 
ule;   decomposed   by  strong   sul- 
phuric acid. 

2-5 

Malleable 
and  sectile 

7-3 

I.  Also  mas- 
sive. 

Uneven. 

Opaque. 

Reactions  for  sulphur  in  open  tube 
and  with  soda;   silver  on  charcoal 
with  soda;    B.  B.  fuses  at  1.5. 

2-4. 

Brittle. 

4.9- 

III.  Scaly  or 

Basal. 

Opaque. 
Sometimes 

B.  B.  infusible;    becomes   magnetic 
on  charcoal  in   R.  F.  ;   soluble  in 

b-3 

magnetic. 

HC1. 

Red  sublimate  in  closed  and  white 

2-5 

Brittle. 

5-8 

III.  Also 
massive. 

Conchoidal. 

Translucent 
to  opaque. 

in  open  tube;   B.  B.  on  charcoal 
fuses  easily  (i);    white  coating; 

Ag  with  soda  in  R.  F. 

B.  B.  infusible;    reactions   for   sul- 

3-5 

Brittle. 

3-9- 

4.2 

I.  Usually 
massive. 

Dodecahe- 
dral,  perfect. 

Opaque. 

phur;  zinc  oxide  coating  with  soda 
on    charcoal;    effervesces   in  hot 

acid,  evolving  H2S. 

2-5 

Brittle. 

i-5 

Compact  to 
laminated. 

Even  to  con- 
choidal. 

Opaque. 

Burns    before   blowpipe;   infusible, 
and  insoluble  in  acids. 

B.    B.   infusible;    water    in    closed 

2-4- 

Earthy  to 
brittle. 

3-4- 

Amorphous. 

Uneven. 

Opaque. 

tube,  amethystine  bead  with  bo- 
rax :  evolves  chlorine  with  HC1. 

IV.  Usually 

B.    B.    infusible;     water   in    closed 

4- 

Brittle. 

4.2- 
4.4 

acicular  or 
columnar. 

Prismatic, 
perfect. 

Opaque. 

tube;   amethystine  bead  with  bo- 
rax; evolves  chlorine  with  HCl. 

B.  B.  fuses  easily  (1.5)  oncha  coal, 

3-4- 

Brittle. 

4-4- 
S-i 

I.  Usually 
massive. 

Uneven. 

Opaque. 

giving    white    coating    andr  sul- 
phurous odor  ,  and  metallic  copper 

with  soda. 

3- 

Brittle. 

4.4 

IV.  Usually 
massive. 

Prismatic, 
perfect. 

Opaque. 

B.  B.  on  charcoal  fuses  easily,giving 
reactions  for  arsenic  and  sulphur, 
and  metallic  copper  with  soda. 

B.  B.  fuses  easily  (  I  )  and  gives  white 

2-5 

Brittle. 

6.25 

IV.  Usually 
massive. 

Imperfect. 

Opaque. 

coating  on  charcoal,  and  a  glob- 
ule of  silver  with  soda  in  R.  F.  ; 

sulphur  fumes  in  open  tube. 

B.  B.  fuses  easily  (i)  and  gives  re- 

2-5- 
3. 

Brittle. 

5-7- 
5-9 

IV.  Often 
massive. 

Imperfect. 

Opaque. 

actions  for    S  and    Sb     in   open 
tube  ;  coating  of  lead  oxide  on  char- 

coal; residue  yields  Cu  with  soda. 

B.  B.  easily  fusible;   green  flame,  or 

2-5- 
3- 

Brittle. 

5-5- 
5-8 

IV.  Often 
massive. 

Prismatic. 

Opaque. 
Dull  black 
tarnish. 

blue  flame  after  moistening  with 
HCl;   copper  with  soda  on  char- 
coal;  sulphur  reactions. 

B.  B.  infusible;  copper  with  soda  on 

3-4- 

Brittle  to 
earthy. 

6.25 

IV.  Usually 
massive  or 
earthy. 

Uneven  or 
earthy. 

Opaque. 

charcoal  ;  green  solution  with  nitric 
acid  ;  green  flame,  or  blue  flame 
after  moistening  with  HCl. 

A.     MINERALS     WITH 


Analytical  Key. 

Species. 

Composition 

Luster. 

Color. 

Streak. 

Streak  bl'k  . 

\  i 

G.  above  5.3 
Reactions 

Arsenic  (3). 

As. 

Metallic. 

White. 

Dark  gray 
to  black. 

c^   ?s 

for  arsenic. 

^  1 

Streak  gray- 
ish green. 

Alabandite  (8). 

MnS. 

Submetallic. 

Iron-black. 

Grayish 
STC'en 

G.  4. 

[Compar»  S.  T. 

5,8,2i.] 

Strongly 
magnetic. 
Malleable. 

Iron  (2). 

Fe. 

Metallic. 

Iron-gray 
to  black. 

Iron-gray 
to  black. 

Strongly 
magnetic. 

Magnetite  (23). 

Fe3O4. 

Metallic. 

Iron-black. 

Black. 

Brittle. 

Compare    Franklin- 

^ttf^a  u  d  Me  n  a  cca  n  lie  . 

Streak   deep 

^•4  —  
Gothite  (29). 

Fe203 
-fH20. 

Adamantine, 
imperfect. 

Brownish 
black. 

Yellow. 

yellow. 

1 

Compare  G. 

Limonite  (30). 

2Fe203 

Submetallic 
to  silky. 

Brown  to 
black. 

Yellow. 

c.  —  Contin 

Streak   deep 
red. 

Hematite  (25). 

H 

Fe203. 

Metallic  to 
dull. 

Iron-black 
to  steel-gray. 

Red. 

1 

ss 

Compare  G. 

Turgite  (28). 

2Fe203 
H-H2O. 

Submetallic. 

Reddish 
black. 

Red. 

il 

a 

1 

Streak  brown. 
H.  4. 

Sphalerite  (8). 

ZnS. 

Resinous  to 
adamantine. 

Black. 

Brown. 

j 

Columnar  or 
acicular. 

Manganite  (29). 

Mn2O3 
+H20. 

Submetallic. 

Iron-black 
to  steel-gray. 

Brown 
and  black. 

yt 

c 

Squarish 
orthorhom- 

Brookite  (27). 

TiO2. 

Metallic  to 
adamantine. 

Black. 

Pale 
yellowish 
brown  to 

<* 

V 

bic  crystals. 

pure  gray. 

'S 

a 

Streak  gray 

Allanite  (62). 

Complex 
silicate. 

Submetallic. 

Black. 

Gray  to 
light  brown. 

£ 

or  grayish 

OJ 

I* 

rt 

OH 

brown. 
Compare   G. 

Chromite  (23). 

FeCr2O4. 

Submetallic. 

Iron-black. 

Light 
grayish 

E 

Compare 

brown. 

§ 

Dysanalyte. 

Brownish 

6 

Streak 
brownish  red 

Menaccanite 

(25)- 

(FeTi)203. 

Submetallic. 

Iron-black. 

red  and 
black. 

V 

and  black. 

0 

Compare 
form. 

Psilomelane 

(32)- 

MnO2 
+H20. 

Submetallic. 

Iron-black. 

Dark  brown. 

Compare   Wad. 

METALLIC     LUSTER. 


37 


H. 

3-5 

Tenacity. 

G. 

Form. 

Cleavage. 

Other 
Properties. 

Confirmatory  Chemical  Tests. 

Brittle. 

5-7 

III.  Massive 
or 
botryoidal. 

Basal, 
imperfect. 

Opaque. 
Dark   gray 
tarnish. 

B.  B.  volatilizes  without  fusing;  gray 
fumes  and  coating  on   charcoal; 
metallic  sublimate  in  closed  tube. 

3-5- 
4- 

Brittle. 

4- 

I.  Usually 
massive. 

Cubic, 
perfect. 

Opaque. 
Brown 
tarnish. 

B.  B.  fuses  at  3;  sulphur  fumes  in 
open  tube;  amethystine  bead  with 
borax  after  roasting;  effervesces 
in  acid,  evolving  H2S. 

4-5- 

Malleable. 

7-3- 
7.8 

I.  Usually 
compact. 

Octahedral, 
usually  none. 

Opaque. 
Strongly 
magnetic. 

B.  B.  infusible;    soluble  in  HC1. 

if 

Brittle. 

5-2 

I.  Usually 
granular. 

Octahedral. 

Opaque. 
Strongly 
magnetic. 

B.  B.  infusible;   soluble  in  HC1. 

5- 
5-5 

Brittle. 

4- 
4-4 

IV.  Colum- 
nar, fibrous 
and  botry- 
oidal. 

Prismatic, 
perfect. 

Opaque. 

B.    B.     infusible;    water   in  closed 
tube;  becomes  magnetic  onchar- 
coal;   soluble  in  HC1. 

5- 

5-5 

£ 

Brittle. 

3-6- 
4- 

Massive, 
fibrous  and 
botryoidal. 

None. 

Opaque. 

Like  gothite. 

Brittle. 

4.9- 

5-3 

III.  Scaly, 
also  massive 
or 
botryoidal. 

Basal. 

Opaque. 
Sometimes 
magnetic. 

B.  B.  infusible;  becomes  magnetic 
on  charcoal;  soluble  in  HC1. 

5-6. 
4- 

Brittle. 

3-5- 
4-5 

Massive  and 
botryoidal. 

None. 

Opaque. 

Like  hematite,  but  yields  water  in 
closed  tube. 

Brittle. 

4- 

I.  Usually 
massive. 

Dodecahe- 
dral,  perfect. 

Opaque. 

B.  B.  infusible;  reactions  for  sul- 
phur; zinc  oxide  coating  with 
soda  on  charcoal;  effervesces  in 
hot  acid,  evolving  H2S. 

4- 

Brittle. 

4.2- 
4.4 

IV.  Usually 
prismatic  or 
columnar. 

Prismatic, 
perfect. 

Opaque. 
Never 
magnetic. 

B.  B.  infusible;  amethystine  bead 
with  borax  ;  water  in  closed  tube  ; 
evolves  chlorine  with  HC1. 

I:5- 

Brittle. 

4- 

3-5- 
4.2 

IV.  Square 
crystals. 

Prismatic, 
indistinct. 

Opaque. 

B.  B.  infusible;   insoluble. 

**• 

Brittle. 

V.  Tabular, 
prismatic 
and  massive. 

In  traces. 

Opaque. 

B.  B.  fuses  (2.5)  with  intumescence 
to  a  magnetic  globule;  gelatinizes 
with  HC1. 

5-5 

Brittle. 

4-3- 
4.6 

I.  Usually 
massive. 

None. 

Opaque. 
Sometimes 
magnetic. 

B.  B.  infusible;  becomes  magnetic; 
green  bead  with  borax. 

5-6. 

Brittle. 

4-5- 
5- 

III.  Massive. 
Often 
tabular. 

None. 

Opaque. 
Often  slight- 
ly magnetic. 

B.  B.  infusible;   reactions  for  iron. 

5-6. 

Brittle. 

3-7- 
4-7 

Compact 
and  often 
botryoidal. 

Even  or 
conchoidal. 

Opaque. 

B.  B.  infusible;  amethystine  bead 
with  borax;  water  in  closed  tube; 
evolves  chlorine  with  HC1. 

A.     MINERALS     WITH 


Analytical  Key. 

Species. 

Composition 

Luster.               Color.                Streak. 

G.  above    7 
Streak  deep 
brown  to 
black 

Wolframite 

(40 

Compare  Colnmbite 
tantalite 

(FeMn) 
W04 

Submetallic. 

Brownish 
black. 

Deep  brown 
te  black. 

e 

V 

o 

Columbite- 
tantalite  (35) 

(FeMn) 
(NbTa)206 

Submetallic. 

Iron-black. 

Brownish 
black. 

j 

It 

G.  above  5.5 

Reddish 

B 

0 

Samarskite  (35) 

Complex 
columl)ate 

Submetallic, 
shining 

Black. 

brown  to 
brownish 

O 

Compare  Cassiterite 

gray. 

*$ 

Franklinite  (23) 

Dark 

G.  below  5.5 

Compare     Menacca 
nite  and  Melaconite 

(FeZnMn)3 

Metallic. 

Iron-black. 

reddish 

[Compare  also  S.  T 

4 

brown. 

12,  28,  31,  89] 

Strongly 

Magnetite  (23). 

Fe304. 

Metallic. 

Iron-black. 

Black. 

magnetic. 

•« 

Emery  (25). 

A1203+ 
Fe304 

Metallic. 

Black  to 
brown 

Black  to 
brown. 

3 

Iron-black 

'•S 

Hema/tite  (2O- 

Fe203. 

Metallic. 

to 

Red. 

a 

Streak  deep 
red. 

H 

steel-gray 

i. 

2 

§ 

Compare  G. 

Turgite  (28). 

2Fe2O3-f- 
H2O 

Submetallic. 

Reddish 
black 

Red. 

8 

1 

0 

Streak   deep 

Gothite  (29). 

Fe203 
+H20. 

Adamantine 
imperfect 

Brownish 
black 

Yellow. 

s 

yellow. 

fci 

£ 

Compare  G. 

Limonite  (30). 

2Fe2O3 
+3H20. 

Submetallio 
to  silky 

Brown  to 
black 

Yellow. 

* 

G.  above  7. 
Streak  deep 
brown  to 

Wolframite 

(40- 
Compare  Columbite- 

(FeMn) 
WO4. 

Submetallic. 

Brownish 
black 

Deep  brown 
to  black. 

black. 

tantalite. 

G.  above  6.5. 

. 

Streak  gray 
or  light 

Cassiterite  (26). 
Compare  Columbite- 

SnO2. 

Adamantine. 

Black. 

Gray  to 
,ight  brown. 

u 

rown. 

tantalite. 

o 

15 

0 

Columbite- 
tantalite  (35). 

(FeMn) 
(NbTa)206. 

Submetallic. 

[ron-black. 

Brownish 
black. 

>o 

G.  above  5.  5. 

Reddish 

Samarskite  (35). 

Complex 
columbate. 

Submetallic 
shining. 

Black. 

brown  to 
brownish 

gray. 

G.  below  5.5 

Franklinite 

(23). 

(FeZnMn)3 
'     04. 

Metallic. 

ron-black. 

Jark  red  dish 
brown. 

Compare  Menacca- 

ntte 

METALLIC     LUSTER. 


39 


H. 

Tenacity. 

G. 

Form. 

Cleavage. 

Other 
Properties. 

Confirmatory  Chemical  Tests. 

5- 
5-5 

Brittle. 

7.2- 
7-5 

V.  Also 
lamellar 
or  massive 

Prismatic, 
perfect 

Opaque  . 

B.  B.  fuses  easily  (2.5-3)10  a  mag- 
netic globule;   reactions  for  man- 
ganese. 

IV.  Crystals 

6. 

Brittle. 

•3 
7.3 

to  coarsely 

Prismatic. 

Opaque. 

B.  B.  infusible. 

massive. 

5-6. 

Brittle. 

ft 

IV.  Also 
massive 

None. 

Opaque. 

B.  B.  fusible  with   difficulty  (4.5)  ; 
emerald-green    bead   with    SPh; 
green  bead  with  soda. 

5-5- 
6-5 

Brittle. 

r  

5-2 

I.  Octahe- 
drons, also 
massive 

Indistinct. 

Opaque. 
Slightly 
magnetic 

B.  B.  infusible;     amethystine   bead 
with    borax;     bluish-green    bead 
with  soda;   coating  of  zinc  oxide 
with  soda  on  charcoal. 

5-5- 
6.5 

Brittle. 

5-2 

I.  Usually 
massive 

Octahedral. 

Opaque. 
Strongly 

B.  B.  infusible;  soluble  in  HC1. 

magnetic 

III.  Coarsely 

Opaque. 

7-9- 

Brittle. 

4.5 

to  finely 

None. 

Strongly 

B.  B.  infusible;  insoluble. 

granular 

magnetic 

5-5- 
6.5 

Brittle. 

4-9- 
5*3 

III.  Scaly, 
also  com- 
pact and 

Basal. 

Opaque. 
Sometimes 

B.  B.  infusible;    becomes  magnetic 
on  charcoal;   soluble  in  HC1. 

botryoidal 

magnetic 

5-6. 

Brittle. 

4-3- 
4-5 

Compact, 
botryoidal 
and  earthy. 

None. 

Opaque. 

Like  hematite;   but  yields  water  in 
closed  tube. 

IV.  Colum- 

B. B.    infusible;    water    in    closed 

5- 
5-5 

Brittle. 

4- 
4-4 

nar,  fibrous 
and  botry- 

Prismatic, 
perfect 

Opaque. 

tube;   becomes   black   and  mag- 
netic on  charcoal  in  R.  F.;   solu- 

oidal. 

ble  in  HC1. 

Massive, 

5- 

5-5 

Brittle. 

J-6- 
4- 

fibrous  and 
botryoidal. 

None. 

Opaque. 

Like  gothite. 

5- 

5-5 

Brittle. 

7-2- 
7-5 

V.  Also 
lamellar 
or  massive. 

Prismatic, 
perfect. 

Opaque. 

B.  B.  fuses  easily  (2.5-3)  to  a  mag- 
netic globule  ;   reactions  for  man- 
ganese. 

A  Q 

II.  Also 

B.  B.  infusible;  insoluble;  with  soda 

6-7. 

Brittle. 

1   I 

massive  and 

Imperfect. 

Opaque. 

on  charcoal  reduced    to  metallic 

botryoidal 

tin. 

6. 

Brittle. 

5-3- 

7-3 

IV.  Usually 
in  crystals. 

Prismatic. 

Opaque. 

3.  B.  infusible. 

5-6. 

Brittle. 

5.6- 

5  8 

IV.  Also 
massive. 

^Jone. 

Opaque. 

B.  B.    fuses    with    difficulty    (4.5); 
emerald-green   bead    with    SPh; 

green  bead  with  soda. 

5-5- 

Brittle. 

5-2 

I.  Octahe- 
drons and 

Indistinct. 

Jpaque. 
Slightly 

3.   B.  infusible;    amethystine    bead 
with  borax  ;  bluish  green  bead  with 

6-5 

massive. 

magnetic. 

soda;    coating  of  zinc  oxide  with 

soda  on  charcoal. 

4° 


A.     MINERALS     WITH 


Analytical  Key. 

Species. 

Composition 

Luster. 

Color. 

Streak. 

Squarish 
orthorhom- 
bic  crystals. 

Brookite  (2^. 

no2. 

Metallic  to 
adamantine. 

Black. 

jray  to 
ight  brown. 

S 
•«* 

s 

"S. 

Rutile  (26). 

TiO2. 

Metallic   to 
adamantine. 

Black. 

Gray  to 
ight  brown. 

1 

1 

2 

Streak   light 

\ 

o 
o 

\ 

g 

gray    to 
grayish 

Allanite  (62). 

Complex 
silicate. 

Submetallic. 

Black. 

Gray  to 
ight  brown. 

$ 

e 

't 

2 

brown. 

1 

3 

Gravish 

| 

Chromite  (23). 

FeCr2O4. 

Submetallic. 

Tron-black. 

brown. 

a 

1 

0 

j!jj 

>* 

O'' 

Streak 
arownishred 

Menaccanite 

OS)- 

(FeTi)2O3. 

Submetallic. 

Iron-black. 

Brownish 
black. 

and  black. 

Compare 
crystalli/a- 
tion. 

Psilomelane 

(32). 

[Compare 

MnOo-h 
H2O. 

Submetallic. 

Tron-black. 

Brownish 
black. 

S.  T.  30,31.] 

Creasy    feel. 
Usually 

Graphitje  (5). 

C. 

Metallic. 

Black  to 
dark  gray. 

Black. 

foliated. 

Folise  not 

elastic. 
Compare  G. 

Molybdenite  (5). 

MoS2. 

Metallic. 

Lead-gray. 

Dark 
lead-gray. 

Malleable 
and  sectile 
Nearlyblack 

Argentine  (6). 

Ag2S. 

Metallic. 

Blackish 
lead,-gray. 

Blackish 
lead-gray. 

G.  above    6 

^ 

Slightly 
sectile. 

Bismuthinite 

Bi  S. 

Metallic. 

Lead-gray 
to 
tin-white 

Dark  gray 
to  black. 

1 

Gray  or 

0 

1 

white 
G.  above    6 

Tetradymite 

Bi2(Te,S)  . 

Metallic. 

Pale 
steel-gray 

Dark  gray 
to  black. 

3 

5~ 

S 

ri 

Brittle. 
Gray  or 

Sylvanite  (12). 

(Au,Ag) 
Te2. 

Metallic. 

Steel-gray 
to 
silver-white 

Dark  gray. 

white 

G.  above   6 

Bismuth  (3). 

Bi. 

Metallic. 

Reddish 
white 

Dark  gray. 

Streak 
black 

Pyrolusite  (27) 

MnO2. 

Metallic. 

Iron-black 
to  gray 

Black. 

G.  below    5 

Compare 
color 

Stibr/ite  (14). 

Sb2S3. 

Metallic. 

Light 
lead-gray 

Dark  gray- 
ish black. 

S/X£.   9,  14,  17,    ig" 

METALLIC     LUSTER. 


H. 

Tenacity. 

G. 

Form. 

Cleavage. 

Other 
Properties. 

Confirmatory  Chemical  Tests. 

r 

Brittle. 

4- 

IV.  Square 
crystals. 

Prismatic, 
indistinct. 

Opaque. 

B.  B.  infusible;  insoluble. 

6- 
6.5 

Brittle. 

4.2 

II.  Prismatic 
and  twin 
crystals. 

Prismatic, 
distinct. 

Opaque. 

B.  B.  infusible  ;  insoluble. 

V.  Tabular, 

B.  B.  fuses  (2.5)  with  intumescence 

^~ 

Brittle. 

3-5 

prismatic 

In  traces. 

Opaque. 

to  a  magnetic  globule;  gelatinizes 

o. 

•* 

and  massive. 

with  HC1. 

5- 
5-5 

Brittle. 

4-3- 
4.6 

I.  Usually 
massive. 

None. 

Opaque. 
Sometimes 
magnetic. 

B.  B.  infusible;  becomes  magnetic; 
green  bead  with  borax. 

5-6. 

Brittle. 

4-5- 
5. 

III.  Often 
laminated. 

None. 

Opaque. 
Often  slight- 

B. B.  infusible;   reactions  for  iron. 

ly  magnetic. 

5-6. 

Brittle. 

3-7- 
4-7 

Compact  or 
botryoidal. 

Even  or 
conchoidal. 

Opaque. 

B.  B.  infusible;     amethystine   bead 
with  borax;  water  in  closed  tube; 
evolves  chlorine  with  HC1. 

1-2. 

Sectile. 

2- 
2.2 

III.  Usually 
foliated. 

Basal, 
perfect. 

Opaque. 
Greasy    feel. 

B.  B.  infusible;  unaltered  by  acids. 

1-5 

Sectile. 

4.6 

III.  Usually 
foliated. 

Basal, 
perfect. 

Opaque. 
Greasy   feel. 

B.  B.  infusible;     reactions   for   sul- 
phur in  open   tube  and  with  soda. 

2. 

Malleable 
and  sectile. 

7-3 

I.  Also 
massive. 

Uneven. 

Opaque. 

Reactions  for  sulphur  in  open  tube 
and  with  soda;   silver  on  charcoal 
with  soda;  B.  B.  fuses  at  1.5. 

2. 

Somewhat 
sectile. 

6.4- 
6.5 

IV.  Acicular 
crystals,  usu- 
ally foliated 
or  fibrous. 

Brachypina- 
coid,  perfect. 

Opaque. 
Yellow 
tarnish. 

B.  B.  fuses  very  readily  (i),  yield- 
ing sulphur  fumes  and  a  yellow 
coating  of  bismuth  oxide  on  char- 
coal. 

Laminae 

III.  Usually 

B.  B.   fuses   easily  and   volatilizes; 

!-5- 

2. 

flexible. 
Slightly 
sectile. 

7.2- 
7-6 

massive, 
foliated  or 
bkded. 

Basal, 
perfect. 

Opaque. 

white   sublimate    in   open   tube; 
white  coating  (TeO2)  on  charcoal, 
followed  by  orange-yellow(Bi.2O3). 

i-5- 

2. 

Brittle. 

7-9- 
8-3 

V.  Usually 
massive, 
columnar  or 

Clinopina- 
coid,  perfect. 

Opaque. 

B.  B.  fuses  easily;  white  coating  on 
charcoal,  and  white  sublimate  in 

bladed. 

open  tube. 

2. 

Brittle. 

IT 

III.  Also 
massive  and 
foliated. 

Basal, 
perfect. 

Opaque. 
Tarnishes. 

B.  B.  fuses  very  readily  (i)  and  vol- 
atilizes,  leaving    yellow    volatile 
coating  on  charcoal. 

IV.  Usually 

B.   B.  infusible;    amethystine   bead 

2. 

Brittle. 

4.8 

columnar  or 

Prismatic. 

Opaque. 

with  borax;  evolves  chlorine  with 

massive. 

HC1. 

2. 

Brittle. 

4-5 

IV.  Colum- 
nar to 
granular. 

Pinacoidal, 
perfect. 

Opaque. 

B.  B.  fuses  very  readily(i)  and  gives 
antimony  fumes   and  coating  on 
charcoal. 

A.     MINERALS     WITH 


Analytical     Key. 

Species. 

Composition 

Luster. 

Color. 

Streak. 

Malleable 
and  sectile. 

Argentite  (6). 

Ag2S. 

Metallic. 

Blackish 
lead-gray. 

Blackish 
lead-gray. 

Color 

bronze-yel- 
ow.  Slightly 

Pyrrhotite  (9). 
Compare  Polydy- 

Fe7S8. 

Metallic. 

Bronze- 
yellow. 

Grayish 
black. 

magnetic. 

mite. 

Arsenic  (3). 

As. 

Metallic. 

Tin-white. 

Dark  gray 
to  black. 

Color    white 

or  nearly 

white  on 
fresh  sur- 

Antimony (3). 

Sb. 

Metallic. 

Tin-white. 

Dark  gray. 

face. 

Compare   G. 

Bismuth  (3). 
Compare        Stibnite 

Bi. 

Metallic. 

Reddish 
white. 

Dark  gray. 

and  Polydymite. 

Color  light 
gray  to  steel- 

Stibnit^  (14). 

Sb2S3. 

Metallic. 

Light 
lead-gray. 

Dark  grayish 
black. 

gray  and 

\ 

^S 

light  lead- 

a 

gray. 
Compare   H 

Polydymite  (9). 

Compare       Arsenic, 
etc.,  Jamesonite  and 

Ni4S5. 

Metallic. 

Light  gray 
to  steel-gray. 

Black. 

o 

Bournonite. 

1 

§ 

Color  dark 

Dark 

Dark 

e$ 

lead-gray. 
j.  above  7. 

Galenite  (6). 

PbS. 

Metallic. 

lead-gray. 

lead-gray  to 
black. 

S 

Chalcocite  (7). 

Cu2S. 

Metallic. 

Blackish 
lead-gray. 

Blackish 
lead-gray  to 
black. 

fci! 

Color  dark 

S 

lead-gray 
to  iron-gray. 

Bournonite  (  1  6). 

PbCuSbS3. 

Metallic. 

Steel-gray  to 
iron-black 

Dark  gray 
to  black. 

G.  5.5-6. 

Jamesonite(i6). 

Pb2Sb2S6. 

Metallic. 

Steel-gray  to 
dark 
lead-gray 

Grayish 
black. 

Color  dark 

lead  -gray 
to  iron-gray 

Tetrahedrite 

(16). 

Cu8Sb2S7. 

Metallic. 

Dark  gray  to 
iron-black 

Dark  gray 
to  black. 

G.  below  5.5 

Color  black 

or  nearly 
black 
G.  above  5.5 

Melaconite  (22). 

Compare.   Chalcocite 
and  xfc7M  rnonite 

CuO. 

Metallic  to 
dull 

Black  to 
gray 

Black. 

Color  black, 
or  nearly 

Manganite  (29). 

3H2O 

Submetallic. 

Iron-black 
to  steel-gray 

Brownish 
black. 

black 

^\ 

G.  below  5. 
Compare  H 

Pyrolusite  (27) 

Compare       Tetrahe- 
drite. [Compare  also 

MnO2. 

Metallic. 

Iron-black 
to  steel-gray 

Black. 

S.  T.4}  5,  6.  7,  12 

16,  17,  18,  19,  20. 

METALLIC     LUSTER. 


43 


H.        Tenacity. 

G. 

Form. 

Cleavage 

Other 
Properties. 

Confirmatory  Chemical   Tests. 

Reactions  for  sulphur  in  open  tube 

Malleable 
'*        and  sectile. 

7-3 

L    A1S°    -       Uneven, 
massive. 

Opaque. 

and  with  soda;   B.  B.  fuses  at  1.5 
on  ch  arcoal,  and  yields  a  globule 

of  silver. 

B.  B.  fuses  easily  on  charcoal  to  mag- 

3'5~ Brittle. 
4- 

4-4- 

4-7 

III.  Usually 
massive. 

Uneven. 

Opaque. 
Tarnishes 
slightly. 

netic  mass,  usually  slightly  mag- 
netic before  fusion  ;  sulph  ur  fumes  ; 
effervesces  with  H  Cl  evolving  H2S. 

3-5      Brittle. 

5-7 

III.  Massive 
or 
botryoidal. 

Basal, 
imperfect. 

Opaque. 
Dark  gray 
tarnish. 

B.  B.  volatilizes  without  fusing,  giv- 
ing  gray  .fumes  and   coating   on 
charcoal,  and   metallic  sublimate 
in  closed  tube. 

Ill    Lamel 

B.  B.  fuses  very  readily  (i)  on  char- 

J~     'Brittle. 

3-5    j 

6.7 

lar  or 
massive 

Basal, 
perfect. 

Opaque. 

coal,  giving  copious  white  fumes 
and    a     volatile     white     coating 

(Sb203). 

~     !  Brittle. 

9-7 

III.  Also 
massive   and 
foliated. 

Basal, 
perfect. 

Opaque. 
Tarnishes. 

B.  B.  fuses  very  easily  (i)  and  vol- 
atilizes,  leaving    yellow    volatile 
coaling  on  charcoal. 

B.  B.   fuses  very   readily    (i)    and 

2-5     '  Brittle. 

4-5 

nar  to 
massive. 

Pinacoidal,    , 
perfect.) 

gives   white  fumes    and    volatile 
white  coating    (Sb2O3)  on  char- 
coal. 

4.5      Brittle. 

tr 

I.  Usually 
massive. 

Cubic, 
imperfect. 

Opaque. 
Yellow 
tarnish. 

Sublimate  of  sulphur  in  closed  tube; 
B.  B.  fuses  easily  to  a  magnetic 
globule  on  charcoal. 

2'5~   Brittle. 
2.75 

7-4- 
7-6 

I.  Cubic 
and  massive. 

Cubic, 
perfect. 

Opaque. 

B.  B.  easily  fusible  (i)  yielding  me- 
tallic lead  and  sulphur  fumes  on 
charcoal. 

i 

B.  B.  easily  fusible;  green  flame,  or 

2'5~  Brittle. 

5-5 
5.8 

IV.  Crystals 
also  massive. 

Prismatic, 
indistinct. 

Opaque. 
Dull  black 

blue  after  moistening  with  HC1; 
copper   with   soda   on   charcoal; 

sulphur  reactions. 

B.  B.  fuses  easily  (i)  ;   reactions  for 

2'5~   Brittle. 

5-7- 

5-9 

IV.  Often 
massive. 

Imperfect. 

Opaque. 

S   and  Sb  in  open  tube;   coating 
of  lead  oxide  on  charcoal;  residue 

yields  copper  with  soda. 

2-3.   Brittle. 

I;5' 

IV.  Usually 
acicular  or 

Basal, 
perfect. 

Opaque. 

B.  B.  fuses  easily  (i);   white  subli- 
mate in  open  tube;   reactions  for 
antimony  and  lead  on  charcoal; 

globules  of  lead  with  soda. 

B.  B.  fuses  easily  (1.5)  on  charcoal, 

3-4.  Brittle. 

4-4- 
5-1 

I.  Usually 
massive. 

Uneven. 

Opaque. 

giving  volatile  white  coating  and 
sulphurous     odor,    and    metallic 

i 

copper  with   soda. 

Brittle  to 
•*                    earthy. 

5-8- 
6.25 

IV.  Usually 
massive  or 

Uneven 
or  earthy. 

Opaque. 

B.  B.  infusible;  copper  with  soda  on 
charcoal;     green    solution    with 
nitric  acid;  colors  flame  green,  or 

y. 

blue  after  moistening  with  HC1. 

4.       i  Brittle. 

4-2- 
4-4 

IV.  Usually 
prismatic  or 
columnar. 

Prismatic, 
perfect. 

Opaque. 

B.  B.  infusible;     amethystine    bead 
with  borax;   water  in  closed  tube; 
evolves  chlorine  with  HC1. 

IV.  Usually 

B.  B.  infusible;     amethystine    bead 

2.5     Brittle. 

4.8 

columnar  or 

Prismatic. 

Opaque. 

with  borax;    evolves  chlorine  with 

massive. 

HC1. 

44 


A.     MINERALS     WITH 


Analytical  Key. 

Species. 

Composition 

Luster. 

Color. 

Streak. 

IV.  Color  Gray.  —  Continued. 

'H 
1 

CO 

Strongly 
magnetic. 
Malleable. 

Iron  (2). 

Te. 

Metallic. 

[ron-gray 
to  black. 

ron-gray 
to  black. 

Strongly 
magnetic. 
Brittle. 

Magnetite  (23). 

Fe3O4. 

Metallic. 

Dark  gray  to 
iron-black. 

Black. 

Slightly  magnetic, 
bronze-yellow  on 
fresh  fracture. 

Pyrrhotite  (9). 

Fe7S8. 

Metallic. 

Bron/.e- 

yellow. 

Grayish 
black. 

Streak  red. 

Hematite  (25). 

Fe203. 

Metallic. 

Steel-gray  to 
iron-black. 

Red. 

Color  iron-black 
o  dark  steel-gray, 
fusible. 

Tetrahedrite 
v    /         C1^). 
\J 

Cu8Sb2S7. 

Metallic. 

Dark  gray  to 
iron-black. 

Dark  gray 
to  black. 

Color  iron-black 
o  dark  steel-gray, 
infusible. 
Crystalline. 

Manganite  (29). 
Compare  Polianite. 

Mn203+ 
H  0. 

Submetallic. 

Iron-black 
to  steel-gray. 

Brown 
and  black. 

I!olor  iron-black 
to  dark  steel-gray, 
infusible.   Com- 
pactor botryoidal. 

Psilomelane 

(32). 

2Mn(Vf 
H2O 

Submetallic. 

Iron-black 
to  steel-gray. 

Dark  brown. 

j.  above  6.5. 
Arsenical  fumes, 
and  odor  on 
charcoal. 

Lollingite  (n). 

Compare  Smaltiie. 

FeAs2. 

Metallic. 

Silver-white 
to  steel-gray. 

Dark 
grayish 
black. 

G.  6  or  above  6. 
Arsenical  fumes 
and  odor  on 
charcoal. 

Cobaltite  (10). 

Smaltite  (10). 

Arsenopyrite 

(11). 

CoAsS. 

(CoFeNi) 
As2. 

FeAsS. 

Metallic. 
Metallic. 
Metallic. 

Silver-white 
to  steel-gray. 

Tin-white 
to  steel-gray 

Silver-white 
to  steel-gray. 

Dark 
grayish 
black. 

Dark 
grayish 
black. 

Dark 
grayish 
black. 

G.  not.  above  5. 
Grayish  yellow  on 
fresh  fracture 

Marcasite  (11). 

Compare  Pyrite. 

FeS2. 

Metallic. 

Pale  grayish 
yellow. 

Dark 
brownish 
black. 

G.  not  above  5. 
Reactions  for 
manganese 

Polianite  (26). 

MnO2. 

Metallic. 

Light  steel- 
gray  or 
iron-gray. 

Black. 

G.  not  above  5. 
Reactions  for  sul- 
phur on  charcoal 
and  in  open  tube 

Polydymite  (9). 

Linnaeite  (10). 
[Compare 
S.  T.  1,12,13.1 

Ni4S5. 
Co3S4. 

Metallic. 
Metallic. 

Light  gray 
to  steel-gray. 

Pale 
steel-gray 

Black. 

grayish 
black. 

METALLIC     LUSTER. 


45 


H. 

Tenacity. 

G. 

Form. 

Cleavage. 

Other 
Properties. 

Confirmatory  Chemical  Tests. 

4-5- 

Malleable. 

7*8 

I.  Usually 
compact. 

Octahedral; 
usually 
none 

Opaque. 
Strongly 
magnetic 

B.  B.  infusible;   soluble  in  HC1. 

5-5 

Brittle. 

5- 

I.  Usually 
granular. 

Octahedral. 

Opaque. 
Strongly 
magnetic 

B.  B.  infusible;   soluble  in  HC1. 

B.  B.  fuses  easily   on    charcoal,    to 

4-5 

Brittle. 

4-5 

III.  Usually 
massive. 

Uneven. 

Opaque. 
Tarnishes. 

magnetic    mass;    usually   slightly 
magnetic  before  fusion;    sulphur 

fumes;   effervesces  with  HC1. 

5-5- 
65 

Brittle. 

4.9- 
5-3 

III.  Scaly, 
massive  or 
botryoidal. 

Basal. 

Opaque. 
Sometimes 
magnetic 

B.  B.  infusible;   becomes   magnetic 
on  charcoal;  soluble  in  HC1. 

B.  B.  fuses  easily  (1.5)  on  charcoal, 

3-4- 

Brittle. 

4.4- 
S-i 

I.  Usually 
massive. 

Uneven. 

Opaque. 

giving  while  coating  and  sulphur- 
ous odor,  and  metallic  copper  with 

soda. 

4- 

Brittle. 

4.2- 
44 

IV.  Usually 
prismatic 
or  columnar. 

Prismatic, 
perfect 

Opaque. 

B.  B.  infusible;     amethystine   bead 
with  borax;  water  in  closed  tube; 
evolves  chlorine  with  HC1. 

5-6. 

Brittle. 

37- 

47 

Compact 
and  often 
botryoidal. 

Even  or 
conchoidal 

Opaque. 

B.  B.  infusible;     amethystine   bead 
with  borax;  water  in  closed  tube; 
evolves  chlorine  with  HC1. 

B.  B.  difficultly  fusible;  sublimate  ol 

S-S 

Brittle. 

6.8- 

7-4 

IV.  Usually 
massive. 

Basal. 

Opaque. 

metallic    arsenic   in  closed  tube; 
white  sublimate  in  open  tube;   ar- 

senical fumes  on   charcoal. 

5-5 

Brittle. 

6- 
6-3 

I.  Also 
massive. 

Cubic, 
perfect 

Opaque. 

B.  B.    fuses  easily;  arsenical  fumes 
and  coating  on  charcoal;    cobalt- 
blue  bead  with  borax. 

Is' 

Brittle. 

6.4- 
6.6 

I.  Usually 
massive. 

Cubic, 
in  traces 

Opaque. 

B.  B.  fuses  easily;  arsenical  coating 
and  magnetic  residue  on  charcoal; 
arsenic  sublimate  in  closed  tube. 

5-5- 
6. 

Brittle. 

6- 
6.4 

IV.  Also 
massive. 

Prismatic, 
distinct. 

Opaque. 

B.  B.  fuses  easily  (2)  giving  arsenical 
coating  and  fumes  and  magnetic 
residue  on   charcoal;  arsenic  sub- 

limate in    closed  tube. 

6 

IV.  Often 

B.  B.  fuses  easily;   magnetic  residue 

6  c 

Brittle. 

4-9 

massive  or 

Prismatic. 

Opaque. 

on  charcoal;  sulphur  sublimate  in 

uo 

globular. 

closed  tube. 

6- 
6.5 

Brittle. 

5- 

II.  Also 
massive. 

Prismatic, 
perfect. 

Opaque. 

B.  B.  infusible;     amethystine    bead 
with  borax;   evolves  chlorine  with 
HC1. 

4-5 

Brittle. 

4-5- 
4.8 

I.  Usually 
massive. 

Cubic, 
imperfect. 

Opaque. 
Yellow 
tarnish. 

Sublimate  of  sulphur  in  closed  tube; 
B.  B.  fuses  easily  to  a  magnetic 
globule  on  charcoal. 

5-5 

Brittle. 

4.8- 
5- 

I.  Usually 
massive. 

Cubic, 
imperfect. 

Opaque. 
Copper-red 
tarnish. 

Reactions  for  sulphur  in  tubes;  B.  B. 
fuses  easily  to  a  magnetic  globule 
on  charcoal. 

A.     MINERALS     WITH 


Analytical  Key. 

Species.            Composition 

Luster.               Color. 

Streak. 

i 

Strongly 

Magnetite  (23). 

Fe304. 

Metallic. 

Iron  -black 
ito  dark  gray. 

Black. 

magnetic. 

Emery  (25). 

FeO4 

Metallic. 

Iron-black 
to  brown. 

Black 
to  brown. 

Streak  red. 

Hematite  (25). 

Fe203. 

Metallic. 

Steel-gray  to 
iron-black. 

Red. 

\/ 

I 

Color  iron-black 
to  dark 
steel-gray. 

Psilomelane 

2MnO2 
+H20 

Submetallic. 

Iron-black 
to  steel-gray. 

Dark  brown. 

i 

G.  above  10. 

Sperrylite  (10). 

PtAso. 

Metallic. 

j  Tin-white. 

Black. 

g 

! 

1 

G.  above  6.6 
Arsenical  fumes 
and  odor  on 
charcoal 

Lollingite  (n). 
Compare  Smaltite. 

FeAs2. 

Metallic. 

Silver-white 
to  steel-gray. 

Dark 
grayish 
black. 

0 

* 

Cobaltite  (10). 

CoAsS. 

Metallic. 

Silver-white 
to  steel-gray. 

Dark 
grayish 
black. 

^o 

G.  6  or  above  6. 

li 

Arsenical  fumes 
and  odor  on 
charcoal. 

Smaltite  (10). 

(CoFeNi) 
As2 

Metallic. 

Tin-white 
to  steel-gray. 

Dark 
grayish 
black. 

Dark 

Arsenopyrite 

(n). 

FeAsS. 

Metallic. 

Silver-white 
to  steel-gray. 

grayish 
black. 

G.  not  above  5. 

Dark 

Grayish  yellow 

Marcasite  (n). 

FeS2. 

Metallic. 

Pale  grayish 

brownish 

on  fresh  fracture. 

Compare  Pyrite. 

yellow. 

black. 

G.  not  above  5. 

Light 

Reactions   or 

Polianite  (26). 

MnOg. 

Metallic. 

steel-gray  or 

Black. 

manganese. 

iron-gray. 

G.  not  above   5. 

Dark 

Reactions  for 
sulphur. 

Linnaeite  (  10). 
[Compare  S.  T.  2.] 

Co3S4. 

Metallic. 

Pale 
steel-gray. 

grayish 

'  black. 

_ 

Liquid. 

Mercury  (2). 

Hg, 

Metallic. 

Tin-white. 

WThite. 

f 

Malleable. 

Silver  (i). 

Ag- 

Metallic. 

Silver-white. 

White. 

rS 

£ 

k° 

^ 

Brittle. 

Bismuth  (3). 

Bi. 

Metallic. 

Reddish 
white. 

Dark  gray. 

[Compare  S.  T.  3.] 

I 

METALLIC     LUSTER. 


47 


H. 

Tenacity. 

G. 

Form. 

Cleavage. 

Other 
Properties. 

Confirmatory  Chemical  Tests. 

6.5 

Brittle. 

5- 

I.  Usually 
granular 

Octahedral. 

Opaque. 
Strongly 

B.  B.  infusible;   soluble  in  HC1. 

magnetic. 

7-9 

Brittle. 

4-5 

III.  Usually 
granular 

None. 

Opaque. 
Strongly 

B.  B.  infusible;  insoluble. 

magnetic. 

If 

Brittle. 

4-9- 
5-3 

III.  Scaly, 
massive  or 
botryoidal 

Basal. 

Opaque. 
Sometimes 
magnetic. 

B.  B.   infusible;   becomes  magnetic 
on  charcoal;  soluble  in  HC1. 

5-6. 

Brittle. 

3-7- 
4-7 

Compact 
and  often 
botryoidal 

Even  or 
conchoidal 

Opaque. 

B.  B.  infusible;     amethystine   bead 
with  borax;  water  in  closed  tube; 
evolves  chlorine  with  HC1. 

B.  B.  fuses  very  easily;  white  subli- 

6-7. 

Brittle. 

10.6 

crystals 

Conchoidal. 

Opaque. 

mate    of  arsenic   oxide   in    open 
tube. 

B.  B.  difficultly  fusible;  sublimate  of 

5- 
5-5 

Brittle. 

6.8- 
7-4 

IV.  Usually 
massive 

Basal. 

Opaque. 

metallic  As  in  closed  tube,  white 
sublimate  in  open  tube;  As  fumes 

and  magnetic  residue  on  charcoal. 

B.  B.  fuses   easily;    arsenical  fumes 

5-5 

Brittle. 

6- 
6-3 

I.  Also 
massive 

Cubic, 
perfect 

Opaque. 

and  coating  on  charcoal;    cobalt- 
blue  bead  with   borax,  after  roast- 

ing. 

B.  B.  fuses  easily;    arsenical  coating 

5-5- 
6. 

Brittle. 

6.4- 
6.6 

I.  Usually 
massive 

Cubic, 
in  traces 

Opaque. 

and  magnetic  residue  on  charcoal  ; 
arsenic  sublimate  in  closed    tube; 

cobalt-blue  bead  with  borax. 

B.  B.  fuses  easily  (2),  giving  arsen- 

6:5~ 

Brittle. 

6— 

6.4 

IV.  Also 
massive 

Prismatic, 
distinct. 

Opaque. 

ical  coating  and  magnetic  residue 
on  charcoal;   arsenic  sublimate  in 

closed  tube. 

6- 

IV.  Often 

B.  B.  fuses  easily;  magnetic  residue 

6.S 

Brittle. 

4.9 

massive  or 

Prismatic. 

Opaque. 

on  charcoal;  sulphur  sublimate  in 

globular,  etc. 

closed  tube. 

6r 

6.5 

Brittle. 

>• 

II.  Also 
massive. 

Prismatic, 
perfect. 

Opaque. 

B.  B.  infusible;    amethystine    bead 
with  borax  ;    evolves  chlorine  with 
HC1. 

5-5 

kittle. 

4.8- 
>• 

I.  Usually 
massive. 

Cubic, 
imperfect. 

Opaque. 
Copper-  red 
tarnish. 

Reactions  for  sulphur  in  tubes;  B.  B. 
fuses  easily  to  a  magnetic  globule 
on  charcoal. 

Jquid. 

3-5 

Fluid 
globules. 

^one. 

Opaque. 

Volatile;   dissolves  in  nitric  acid. 

2-5- 
3- 

Malleable. 

o-5 

.  Grains, 
scales  and 

Vone. 

3paque. 
Tarnishes 

B.  B.  fuses  easily  (2.5);   soluble  in 
nitric  acid;    dilute  solution  gives  a 

threads. 

black. 

precipitate  with  HC1. 

2- 

2-5 

Brittle. 

•7 

III.  Also 
massive  and 
foliated. 

Basal, 
perfect. 

)paque. 
Tarnishes. 

B.  B.  fuses  very  readily  (i)  and  vol- 
atilizes,   leaving    yellow    volatile 
coating  on  charcoal. 

A.     MINERALS  WITH 


Analytical    Key. 

Species. 

Composition 

Luster. 

Color. 

Streak. 

Malleable. 

Silver  (i). 

Ag- 

Metallic. 

white. 

Vhite. 

^ 

Arsenic  (3). 

As. 

VIetallic. 

Tin-white. 

Dark  gray 
to  black. 

* 

^ 

Brittle. 

Antimony  (3). 

Sb. 

Metallic. 

fin-white. 

Dark  gray. 

Compare  G. 

Reddish 

Bismuth  (3). 

Bi. 

Metallic. 

white. 

Dark  gray. 

[Compare  S.  T.  3,6. 

G.  above  6.6 

pv         V. 

Arsenical  fumes 
and  odor  on 
charcoal. 

Lollingite  (n). 
Compare  Smaltite. 

FeAs2. 

Metallic. 

Silver-white 
o  steel-gray. 

grayish 
black. 

Cobaltite  (10). 

CoAsS. 

Metallic. 

Silver-white 
to  steel-gray. 

Dark 
grayish 
black. 

V 

. 

j.  6  or  above  6. 

Dark 

S 

1 

Arsenical  fumes 
and  odor  on 

Smaltite  (10  . 

(CoFeNi) 
As? 

Metallic. 

Tin-white 
to  steel-gray. 

gravish 
black 

S 

charcoal. 

S 

aj 

( 

i 

Arsenopyrite 

(n). 

FeAsS. 

Metallic. 

Silver-white 
;o  steel-gray. 

grayish 
black. 

fR 

S* 

j.  not  above  5. 

Pale 

Dark 

5 

§ 

Reactions  for 
sulphur. 

Linnaeite  (10). 

[CompareS.  T.  i,  13.] 

Co3S4. 

Metallic. 

steel-gray. 

grayish 
black. 

G.  above  10. 

Sperrylite  (10). 

PtAs2. 

Metallic. 

Tin-white. 

Black. 

G.  above  6.6 
Arsenical  fumes 
and  odor  on 

Lollingite  (11). 

FeAs2. 

Metallic. 

Silver-white 
to  steel-gray 

Dark 
grayish 
black. 

charcoal. 

Compare  Smaltite. 

^5 

Dark 

i 

Cobaltite  (10). 

CoAsS. 

Metallic. 

Silver-white 
to  steel-gray 

grayish 
biack  . 

k« 

G.  6  or  above  6. 

Dark 

^ 

Arsenical  fumes 
and  odor  on 

Smaltite  (10). 

(CoFeNi) 
As2. 

Metallic. 

Tin-white 
to  steel-gray 

grayish 
black 

charcoal. 

Arsenopyrite 

CO 

FeAsS. 

Metallic. 

Silver-white 
to  steel-gray 

Dark 
gravish 
black. 

G.  not  above  5. 

Dark 

Reactions  for 
sulphur. 

Linnaeite  (10). 
[Compare  S.  T.  2.] 

Co3S4. 

Metallic. 

steel-gray 

grayish 
black. 

METALLIC  LUSTER. 


49 


H. 

Tenacity. 

G. 

Form. 

Cleavage. 

Other 
Properties. 

Confirmatory  Chemical  Tests. 

2-5- 

Malleable. 

10.5 

I.  Grains, 
scales  and 

None. 

Opaque. 
Tarnishes 

B.  B.  fuses  easily  (2.5);   soluble  in 
nitric  acid;   dilute  solution  gives 

• 

wires. 

black 

a  white  precipitate  with  HC1. 

3-5 

Brittle. 

5-7 

III.  Massive 
and  botry- 
oidal. 

Basal, 
imperfect. 

Opaque. 
Dark  gray 
tarnish 

B.  B.  volatilizes  without  fusing;  gray 
fumes   and    volatile     coating    on 
charcoal,  and  metallic  sublimate 
in  tube. 

Brittle  or 

III.  Lamel- 

Basil 

B.  B.  fuses  very  readily  (i)  on  char- 

3-5 

slightly 
malleable. 

6.7 

lar  or 
massive. 

perfect. 

Opaque. 

coal,  giving  copious  white  fumes 
and  volatile  coating. 

2- 
2.5 

Brittle  to 
semi- 
malleable. 

9-7 

III.  Also 
massive  and 
foliated. 

Basal, 
perfect. 

Opaque. 
Tarnishes. 

B.  B.  fuses  very  readily  (i)  and  vol- 
atilizes,   leaving   yellow,   volatile 
coating  on  charcoal. 

B.  B.  difficultly  fusible;  sublimate  of 

5- 

5-5 

Brittle. 

6.8- 

7.4. 

IV.  Usually 
massive 

Basal. 

Opaque. 

metallic  As  in  closed  tube;   white 
sublimate  in  open  tube;  As  fumes 

and  magnetic  residue  on  charcoal. 

5-5 

Brittle. 

6- 
6-3 

I.  Crystals 
like  pyrite, 
and  massive. 

Cubic, 
perfect. 

Opaque. 

B.  B.  fuses  easily;   arsenical   fumes 
and  coating  on  charcoal;   cobalt- 
blue  bead  with  borax,  after  roast- 

ing. 

5-5- 

Brittle. 

6.4 
6.6 

I.  Hemihe- 
dral,  usually 
massive,  or 

Octahedral, 
in  traces. 

Opaque. 
Tarnishes 

B.  B.  fuses  easily;  arsenical  coating 
and  magnetic  residue  on  charcoal; 
As  sublimate  in  tube;  cobalt-blue 

reticulated. 

bead  with  borax,  after  roasting. 

5-5- 
6. 

Brittle. 

6- 
6.4 

IV.  Wedge- 
shaped  and 
twin  crystals, 

Prismatic, 
distinct. 

Opaque. 
Tarnishes 

B.  B.  fuses  easily  (2)  giving  arseni- 
cal coating  and  magnetic  residue 
on  charcoal;   arsenic  sublimate  in 

also  massive. 

closed  tube. 

5-5 

Brittle. 

4-8- 
5- 

I.  Usually 
massive. 

Cubic, 
imperfect. 

Opaque. 
Copper-red 
tarnish 

Reactions  for  sulphur  in  tubes;   B. 
B.  fuses  easily  to  a  magnetic  glob- 
ule on  charcoal;   cobalt-blue  bead 

1 

with  borax  after  roasting. 

6-7. 

Brittle. 

10.6 

I.  Minute 
crystals. 

Conchoidal. 

Opaque. 

B.  B.  fuses  very  easily;  white  subli- 
mate of  arsenic  oxide  in  open  tube. 

B.  B.  difficultly  fusible;  sublimate  of 

5- 
5-5 

Brittle. 

6.8- 
7-4 

IV.  Usually 
massive. 

Basal. 

Opaque. 

metallic  As  in  closed  tube;   white 
sublimate  in  open  tube;  As  fumes 

and  magnetic  residue  on  charcoal. 

T     ("Vvsfalc 

13.  B.  fuses  easily;    arsenical  fumes 

5-5 

Brittle. 

6- 
6-3 

like  pyrite, 
and  massive. 

Cubic, 
perfect. 

Opaque. 

and  coating  on  charcoal;    cobalt- 
blue  bead  with  borax,  after  roast- 

ing. 

I.  Hemihe- 

[5.  B.  fuses  easily;   arsenical  coating 

r 

Brittle. 

6.4- 
66 

dral,  usually 
massive,  or 

Octahedral, 
in  traces. 

Tarnishes 

and  magnetic  residue  on  charcoal; 
As  sublimate  in  tube;   cobalt-blue 

reticulated. 

slightly. 

bead  with  borax,  after  roasting. 

r 

Brittle. 

6~ 
6.4 

IV.  Wedge- 
shaped  and 
:\vin  crystals, 
also  massive. 

Prismatic, 
distinct. 

Opaque. 
Tarnishes 
yellowish. 

3.  B.  fuses  easily  (2)  ,giving  arsenical 
coating  and  magnetic  residue  on 
charcoal;     arsenic    sublimate    in 
closed  tube. 

Reactions  for  sulphur  in  tubes;   B. 

5-5 

Brittle. 

4.8- 

5. 

I.  Usually 
massive. 

Cubic, 
imperfect. 

Copper-red 

B.  fuses  easily  to  a  magnetic  glob- 
ule on  charcoal;  cobalt-blue  bead 

with  soda  after  roasting. 

B.     MINERALS     WITHOUT 


Analytical     Key.                         Species. 

Compobition 

Luster. 

Color. 

Streak. 
Red. 

Color  and 
streak  red. 

Turgite  (Red 
Ocher)  (28). 

3H2O. 

Dull. 

Red. 

Earthy. 
Compare  G. 

Kaolinite  (Red 
Clay)  (79)- 

Al2Si2O7 
-f-2H20. 

Dull. 

Red. 

Red. 

Compare  Hematite. 

Realgar  (13). 

AsS. 

Resinous. 

Aurora-red 
and  orange. 

Orange  to 
aurora-red. 

Streak  red. 

Proustite  (16). 

AgaAsSg. 

Adamantine 
to  dull. 

Scarlet- 
vermilion. 

Scarlet- 
vermilion. 

i 

Crystalline. 
Compare  G. 

Pyrargyrite(i6). 

Ag3SbS3. 

Adamantine 
to  dull. 

Black  to 
deep  red. 

Purplish 
red. 

g 

o 

1 

c 

** 

Cinnabar  (9). 
G.  varies  ivitk  impu- 
rity from  3  to  8. 

HgS. 

Adamantine 
to  dull. 

Cochineal- 
red 
to  brown 

Scarlet. 

Streak  deep 
yellow  to 
yellowish  brown. 
Earthy. 

Limonite  (Yel- 
low Ocher)    (30). 
Compare  Kaolinite. 

2Fe203-f- 

Dull. 

Yellow 
to  brown 

Yellow 
to  brown. 

Streak  dark 
brown  to  black. 

Asphaltum  (84). 

C,H,O,  etc. 

\esinous. 

Brownish 
black 
to  black 

Dark  brown 
to  black. 

4* 

G.  I  to  2. 

^ 

— 

Combustible. 

Mineral  Coal 

(84)- 

C,H,O,  etc. 

Resinous. 

Brown 
to  black. 

Dark  brown 
to  black. 

Streak  dark 
brown  to  black. 
G.  3  to  4. 
Incombustible. 

Wad  (32). 
Compare 
S.  T.  29,  46.] 

2Mn02+ 
H2O. 

Dull. 

Brownish 

black. 

Brownish 

black. 

Streak  orange. 
G.  above  5. 

Zincite  (21). 

ZnO. 

Sub- 
adamantine. 

Red 

to  orange. 

Orange. 

Streak  deep 
yellow  to  brown. 

Limonite  (30). 

2Fe2O3— 
3H20. 

Submetallic 
to  dull. 

Dark  brown 
to  yellow. 

Yellow 
to  brown. 

Become 

1 

magnetic  on 
charcoal  B.  B. 

Siderite  (45). 

FeCO3. 

Vitreous 
to  dull. 

Gray  to 
dark  brown. 

Light  gray 
to  brown. 

Compare  Gothite. 

Streak  light 
to  dark  brown. 
Crystalline. 

Sphalerite  (8). 

ZnS. 

Resinous. 

Brown 
to  black. 

Yellow 
to  brown. 

Streak  dark 
brown  to  black. 
Compact  or 
earthy. 

Wad  (32). 

2MnO2+ 
H2O. 

Dull. 

Brownish 
black. 

Brownish 
black. 

METALLIC     LUSTER. 


H.  (Tenacity     G. 

Form. 

Cleavage. 

Other 
Properties. 

Confirmatory   Chemical  Tests 

B.B.  infusible;  water  in  closed  tube; 

2  <i 

Earthy. 

3-4- 

Compact. 

Earthy. 

Opaque, 

becomes   black  and  magnetic  on 

charcoal;   soluble  in  HC1. 

°-5- 

Plastic  to 
earthy. 

2.6 

IV.  Usually 
compact 
or  clayey. 

Earthy. 

Opaque. 

3.B.  infusible;  yields  water  in  closed 
tube;   insoluble. 

'•5- 

Brittle. 

3.5 

V.  Also 

Clinopina- 
coidal  and 

Transparent 
to 

B.  B.  volatile  and  combustible,  burn- 
ing with  a  blue  flame  and  arseni- 

2. 

massive. 

basal. 

translucent. 

cal  odor. 

B.  B.  fuses  readily  (i);  white  subli- 

2- 
2-5 

Brittle. 

5.6 

III.  Also 
massive. 

Conchoidal. 

Translucent 
to  opaque 

mate  in  open  tube;   fumes  of  sul- 
phur   and    arsenic   on   charcoal; 

globule  of  silver  with  soda  in  R.  F. 

B.  B.  fuses  readily  (i);  white  subli- 

2-5 

Brittle. 

5.8 

III.  Also 
massiveo 

Conchoidal. 

Translucent 
to  opaque 

mate  in    open  and  red  in  closed 
tube;  white  fumes  and  coating  on 

charcoal;  Ag  with  soda  in  R.  F. 

2- 
2-5 

Brittle  to 
sectile. 

8- 

8.2 

III.  Usually 
massive. 

Uneven. 

Usually 
opaque 

B.  B.  volatile;    with  soda  in  closed 
tube  yields  a  sublimate  of  mercury. 

B.  B.    infusible;     water    in    closed 

I— 

2-5 

Earthy. 

3-«~ 
4= 

Compact. 

Earthy. 

Opaque. 

tube;    becomes   black  and  mag- 
netic on  charcoal;  soluble  in  HCL 

Brittle  to 

«-S 

flexible. 

1.8 

Amorphous. 

ConchoidaL 

Opaque. 

Fuses  and  burns  with  flame 

2-5 

Brittle. 

1.8 

Amorphous, 
often  laminated. 

Even  or 
Conchoidal. 

Opaque. 

B.  B.  infusible;   but  readily  ignited, 
burning  with  flame. 

B.  B.   infusible;     water    in    closed 

2.5 

Earthy. 

3- 

42 

Amorphous. 

Earthy. 

OpaquCo 

tube;   amethystine  bead  with  bo- 

rax;  evolves  chlorine  with  HC1. 

4- 

4-5 

Brittle. 

5-4- 
5-7 

III.  Lamellar, 
also  massive. 

Basal, 
perfect. 

Usually 
opaque 

B.  B.  infusible;  soluble  in  acid;  zinc 
oxide  coating  with  soda  on  char° 
coal  in  R.  F. 

2-5- 

4- 

Brittle. 

3-6- 
4- 

Compact, 
fibrous  and 
botryoidal. 

None. 

Opaque. 

Water   in   closed  tube;    black  and 
magnetic  on  charcoal. 

3-5- 
4- 

Brittle. 

3-8 

III.  Also 
compact. 

Rhombohe- 
dral,  perfect. 

Translucent 
to  opaque 

B.  B.  infusible;    blackens   and   be- 
comes magnetic;  effervesces  in  hot 
acid,  evolving  CO^. 

B.  B.  infusible;     reactions   for   sul- 

3-5- 

Brittle 

39- 

I.  Also 

Dodecahe- 

Translucent 

phur  ;  zinc  oxide  coating  with  soda 

4- 

4.1 

massive. 

dral,  perfect. 

to  opaque 

on  charcoal;    effervesces  in   hot 

acid,  evolving  H2S. 

2-5- 
4- 

Brittle  to 
earthy. 

<j  

4.2 

Amorphous. 

Uneven 
to  earthy. 

Opaque. 

B.  B.  water  in  closed  tube;  amethys- 
tine  bead   with   borax;     evolves 
chlorine  with  HCL 

B.     MINERALS     WITHOUT 


Analytical  Key. 

Species. 

Composition 

Luster. 

Color. 

Streak. 

Turgite  (28). 

2Fe2O3+ 
H20. 

Submetallic 
to  dull. 

Red  to 
black. 

Red. 

Streak  red. 

Become  mag- 
netic on  char- 
coal B.  B. 

Hematite  (25). 

Fe203. 

Metallic 
to  dull. 

Red  to 
steel-gray 
and  black. 

Red. 

Compare  G. 

1 

Cuprite  (20). 

Cu2O. 

Adamantine 
to  dull. 

Red  to 
brown. 

Red  to 
brown. 

•H 

Compare  Siderite. 

( 

Proustite  (16). 

Ag3AsSg. 

Adamantine 
to  dull- 

Scarlet- 
vermilion. 

Scarlet- 
vermilion. 

< 

Streak  red. 
Do  not  become 

Pyrargyrite(i6). 

AggSbSg. 

Adamantine 
to  dull. 

Black  to 
deep  red. 

Purplish  red. 

magnetic  on 

charcoal  B.  B. 
Compare  G. 

Cuprite  (20). 

Cu20. 

Adamantine 
to  dull. 

Red  to 
brown. 

Brownish 
red. 

$ 

2 

Cochineal- 

so 

1 

\ 

Cinnabar  (9). 
[Compare    S.  T. 

HgS. 

Adamantine 
to  dull. 

red  to 
brownish 
red. 

Scarlet. 

\ 

29t   31.  43,44-] 

g 

I 

Streak  orange. 
G.  above  5. 

Zincite  (21), 

ZnO. 

Sub- 
adamantine. 

Dark  red 
to  orange. 

Orange. 

Color  brown 
to  black. 

Limonite  (30). 

2Fe2O3 
+3H20. 

Submetallic 
or  silky 
to  dull. 

Brown  to 
black. 

Yellow 
to  brown. 

§ 

Streak   deep 

•fe 

yellow  to 
brown. 
G.  below  5. 

Gothite  (29). 

Fe203 
•     +HaO. 

Adamantine 
to  dull. 

Brown  to 
black. 

Yellow 
to  brown. 

Become  mag- 

7! 

netic  on 
charcoal  B.  B. 

Siderite  (45). 

FeC03. 

Vitreous. 

Gray  to 
dark  brown. 

Light  gray 
to  brown. 

CO 

Color  brownish 
black. 
G.  above  7. 

Wolframite 

(40. 

(FeMn) 
WO4. 

Submetallic. 

Brownish 
black. 

Deep 
reddish 
brown  to 
black. 

Reddish 

Samarskite(35). 

Complex 
columbate. 

Submetallic, 
shining. 

Black. 

brown  to 
brownish 

Color  black. 

gray. 

G.  above  5.5. 

Dark  red, 

Columbite- 
tantalite  (35). 

FeCb2O6. 

Submetallic. 

Black. 

grayish 
brown  and 

black. 

Color  brown  to 

black.   Streak 
yellow  to  brown. 

Sphalerite  (8). 

ZnS. 

Resinous. 

Brown  to 
black. 

Yellow 
to  brown. 

G.  about  4. 

METALLIC     LUSTER. 


53 


H.     Tenacity 

G. 

Form. 

Cleavage. 

Other 
Properties. 

Confirmatory  Chemical  Tests. 

Compact,  also 

B.  B.  decrepitates;   infusible;  yields 

2-5~ 

Brittle. 

3-5" 

fibrous  and 

None. 

Opaque. 

water   in    closed    tube;    becomes 

4- 

4-5 

botryoidal. 

black  and  magnetic  on  charcoal. 

3-4- 

Brittle. 

4-9- 

5-3 

III.  Scaly,  also 
compact  and 
botryoidal. 

Basal. 

Opaque. 
Sometimes 
magnetic. 

Like  turgite;   but  no  water  in  tube, 
and  no  decrepitation. 

3-5- 

4- 

Brittle. 

5.8- 
6.1 

I.  Also  capillary 
or  acicular 

Octahedral. 

Transparent 
to  opaque. 

B.  B.  colors  flame  green   and  fuses 
readily,   yielding  metallic  copper 
on  charcoal  ;     becomes  magnetic 

and  massive. 

whenimpure;  blue  flame  with  HC1. 

2- 

III.  khombohe- 
dral;  also 

Fracture 

Transparent, 
to 

B.  B.  fuses  readily  (i);  white  subli- 
mate in  open  tube;  arsenical  and 

2-5 

Brittle. 

5-6 

massive  and 

conchoidal. 

tr3,ns  lucent. 

sulphurous    fumes   on     charcoal; 

compact. 

globule  of  Ag  with  soda  in  R.  F. 

B.  B.  fuses  readily  (i)  ;  white  subli- 

III. Prismatic, 

Fracture 

Translucent 

mate  in  open,  red  in  closed  tube; 

2-5 

Brittle. 

5.8 

also  massive 

conchoidal. 

to  opaque. 

white  coating,  sulphurous  fumeson 

and  compact. 

ch  ,  globule  of  Ag  with  sodain  R.  F. 

3-5- 
4- 

Brittle. 

5.8- 
6.1 

I.  Octahedrons, 
etc.,  also 
capillary  and 
massive. 

Octahedral. 
Fracture 
conchoidal. 

Translucent 
to  opaque. 

B.  B.  colors  flame  green  and  fuses 
readilv,  yielding  metallic  copper; 
blue  flame  after  moistening  with 
HC1. 

2- 

Brittle 

8- 

III.  Usually 

Fracture 

Transparent 

B.  B.  volatile;   with  soda  in  closed 

2-5 

tosectile. 

8.2 

massive  or 

uneven. 

to  opaque. 

tube  yields  a  sublimate  of  mercury. 

compact. 

4- 
4-5 

Brittle. 

54- 

5-7 

III.  Usually 
massive  or 
lamellar. 

Basal 
perfect. 

Usually 
opaque. 

B.  B.  infusible;  soluble  in  acid  ;  zinc 
oxide  coating  with  soda  on  char- 
coal in  R.  F. 

Compact, 

Uneven, 

B.  B.    infusible;    water    in    closed 

4~ 

5-5 

Brittle. 

3-6- 

4- 

botryoidal, 
fibrous,  etc. 

splintery, 
etc. 

Opaque. 

tube;   becomes   black   and  mag- 
netic on  charcoal;  soluble  in  HC1. 

IV.  Usually 

5- 
5-5 

Brittle. 

4- 
4.4 

massive, 
fibrous  or 

Pinacoidal, 
perfect. 

Opaque. 

Like  limonite. 

botryoidal. 

3-5- 
4- 

Brittle. 

3-8 

III.Rhombohe- 
dral,  also 
massive  or 

Rhombohe- 
dral,  perfect. 

Translucent 
to  opaque. 

B.  B.  infusible;    blackens   and   be- 
comes magnetic;     effervesces   in 
hot  acid,  evolving  CO2. 

compact. 

V.  Prismatic,  or 

5- 
5-5 

Brittle. 

7-2- 
7-5 

bladed,  also 
lamellar  or 

Prismatic, 
perfect. 

Opaque. 

B.  B.  fuses  (3)  to  a  magnetic  glob- 
ule; reactions  for  manganese. 

massive. 

-   £. 

IV.  Crystals, 

Imperfect. 

B.  B.  fusible  .with   difficulty  (4.5); 

5-6. 

Brittle. 

3.0- 

-    o 

also  massive 

Fracture 

Opaque. 

emerald-green   bead   with    SPh; 

»? 

5-8 

or  in  grains. 

conchoidal 

green  bead  with  soda. 

IV.  Usually  in 

Pinacoidal. 

6. 

Brittle. 

5-5- 

crystals,  some- 

Fracture 

Opaque. 

B.  B.  infusible. 

7-3 

times  massive. 

uneven. 

3-5- 

4- 

Brittle. 

3-9- 
4.1 

I.  Tetrahedral, 
also  massive 
or  granular. 

Dodecahe- 
dral,  perfect. 

Translucent 
to  opaque. 

B.  B.  infusible;    reactions   for   sul- 
phur;    zinc   oxide   coatings  with 
soda  on  charcoal;    effervesces  in 

hot  acid,  evolving  H2S. 

B.     MINERALS     WITHOUT 


Analytical  Key. 

Species. 

Composition 

Luster. 

Color. 

Streak. 

^olor  black. 

Streak  light 
grayish  brown. 

Chromite  (23). 

FeCr204. 

Submetallic. 

[ron-black. 

Light 
grayish 

j.  below  5. 

brown. 

Color  black. 
Streak  brownish 

Menaccanite 

(25). 

(FeTi)2Oa. 

Submetallic. 

Iron-black. 

Brownish 
redand 

red  to  black. 

black. 

G.not  above  5. 

1 

Compare  cryst- 
allization. 

Psilomelane 

(32). 

MnOo-f- 
H2O. 

Submetallic. 

Iron-black. 

Dark  brown. 

1 
\ 

Streak  red. 
Become 

Turgite  (28). 

2Fe203+ 
H2O. 

Submetallic 
to  dull. 

Reddish 
black. 

Red. 

^ 

magnetic  on 

1 

charcoal  B.  B. 
Compare  G. 

Hematite  (25). 

Fe203. 

Metallic 

Reddish 
black  to 

Red. 

09 

Compare  Cuprite. 

steel-gray. 

1 

Streak  red. 
Do  not  become 

Cuprite  (20). 

Cu2O. 

Adamantine 
to  dull. 

Red  to 
brown. 

Red  to 
brown. 

| 

magnetic  on 
charcoal  B.  B. 

Cochineal- 

a 

Compare  G. 

Cinnabar  (9). 

[Compare 

HgS. 

Adamantine 
to  dull. 

red  to 
brownish 

Scarlet. 

. 

S.  T.  36,  37,41-1 

red. 

§ 

Streak  bright 

| 

red. 
Compare 

Turgite  (28). 

2Fe203+ 
H2O. 

Submetallic. 

Reddish 
black. 

Red. 

o 

Hematite. 

•4) 

Cassiterite  (26). 

SnO2. 

Adamantine. 

Brown 
to  black. 

Gray  to 
light  brown. 

s 

G.  above  5.5. 

Columbite- 
tantalite   (35). 

(FeMn) 
(NbTa)2O6. 

Submetallic. 

Black. 

Brownish 
black. 

Reddish 

G 

Samarskite  (35). 

Complex 
columbate. 

Submetallic, 
shining. 

Black. 

brown  to 
brownish 

gray- 

£. 

G.  below  5.5. 

Menaccanite 

(25). 

(FeTi)203. 

Submetallic. 

Iron-black. 

Brownish 
black. 

^ 

Color  black. 

Compare  cryst- 
allization. 

Psilomelane 

(32). 

Mn02+ 
H2O. 

Submetallic. 

Iron-black. 

Brownish 
black. 

G.  below  4.5  and 
above  4. 
Color  reddish 

Rutile  (26). 

Ti02. 

Adamantine. 

Reddish 
brown  to 

Light 
brown. 

brown  to  red. 

red. 

G.  below  3. 
Color  red  to 
brown. 

Quartz  (Ferrugi- 
nous Quartz    and 
Jasper)  (33). 

Si02-h 
Fe2O3. 

Vitreous  to 
nearly  dull. 

Red  to 
brown. 

Light  red 
to  brown. 

METALLIC     LUSTER. 


55 


H. 

Tenacity 

G. 

Form. 

Cleavage. 

Other 
Properties. 

Confirmatory  Chemical  Tests. 

5-5 

Brittle. 

4-3- 
4.6 

I.  Usually 
massive,  or 
imbedded 
grains 

None. 
Fracture 
uneven 

Opaque. 
Sometimes 
magnetic 

B.  B.  infusible;   becomes  magnetic; 
green  bead  with  borax. 

III.  Often  lam- 

N 

Opaque. 

5-6. 

Brittle. 

4-5- 

5- 

inated,  or  tabu- 
lar, massive 

Fracture 
conchoidal 

Often 
slightly 

B.  B.  infusible;  reactions  for  iron. 

or  compact 

magnetic 

5-6. 

Brittle. 

37- 
47 

Compact  and 
often  botryoidal 

Even  or 
conchoidal 

Opaque. 

B.  B.  infusible;     amethystine   bead 
with  borax;  water  in  closed  tube; 
evolves  chlorine  with  HC1. 

4-6. 

Brittle. 

4-3- 
47 

Massive  and 
botryoidal 

Fracture 
uneven 

Opaque. 

B.  B.  infusible;  water  in  closed  tube; 
becomes  black  and  magnetic  on 
charcoal;  soluble  in  HC1. 

4-6. 

Brittle. 

4-9- 

5-3 

III.  Scaly,  also 
massive  or 
botryoidal 

Basal. 

Opaque. 
Sometimes 
magnetic 

B.  B.  infusible;    becomes  magnetic 
on  charcoal. 

3-5- 

4- 

Brittle. 

5.8- 
6.1 

I.  Crystals,  also 
capillary  and 

Octahedral. 

Translucent 
to  opaque 

B.  B.  colors  flame  green  and   fuses 
readily,  yielding  metallic  copper  on 
charcoal;    blue  flame  after  moist- 

ening with  HC1. 

4- 

Brittle 

tosectile. 

8- 

8.2 

III.  Usually 
massive  to 
compact. 

Fracture 
uneven 

Usually 
opaque 

B.  B.  volatile;   with  soda  in  closed 
tube  yields  a  sublimate  of  mercury. 

5-6. 

Brittle. 

4-3- 
47 

Compact  and 
botryoidal. 

Fracture 
uneven 

Opaque. 

B.  B.  infusible;  becomes  black  and 
magnetic  on  charcoal,  soluble  in 
HC1;   water  in  closed  tube. 

6-5 

Brittle. 

6.8 

II.  Also 
massive  and 
botryoidal. 

[mperfect. 

Translucent 
to  opaque 

B.  B.  infusible;    yields  metallic   tin 
with  soda  on  charcoal. 

IV.  Usually  in 

6. 

Brittle. 

5-3~ 
1-3 

crystals,  also 

Prismatic. 

Opaque. 

B.  B.  infusible. 

massive. 

6. 

Brittle. 

5-6- 

58 

IV.  Also 
massive  to 

Uneven  or 
conchoidal 

Opaque. 

B.  B.  fusible  with   difficulty  (4.5)  ; 
emerald-green   bead    with   SPh; 

compact. 

fracture 

green  bead  with  soda. 

III.  Often  lami- 

Opaque. 

5-6. 

Brittle. 

4-5- 
>. 

nated,  or  tabu- 
lar, massive 
or  compact. 

JNone. 
Fracture 
conchoidal. 

Often 
slightly 
magnetic. 

B.  B.  infusible;   reactions  for  iron. 

5-6. 

Brittle. 

37- 
47 

Compact  and 
often  botryoidal. 

Even  or 
conchoidal. 

Opaque. 

3.  B.  infusible;     amethystine   bead 
with  borax;  water  in  closed  tube; 
evolves  chlorine  with  HC1. 

6- 
6-5 

Brittle. 

4-2 

I.  Prismatic 
and  twin 
crystals. 

3rismatic, 
distinct. 

Translucent 
to  opaque. 

3.  B.  infusible;   insoluble. 

7- 

Brittle. 

2.6 

III.  Often 
massive  or 

^one. 

Translucent 
to  opaque. 

5.  B.  infusible;  insoluble. 

compact. 

B.     MINERALS     WITHOUT 


Analytical  Key. 

Species. 

Composition 

Luster. 

Color. 

Streak. 

Burns  like 

Yellow 

sulphur.  Sulphur  (4). 

S. 

Resinous. 

Yellow. 

to  white. 

G.  2. 

1 

Earthy. 
G.  above  2.5 

Kaolinite  (Yel- 
low Clay)  (79). 

Al2Si2O7 
-f2H2O. 

Dull. 

Yellow. 

Yellow. 

I 

I-} 

Limonite  (Yel- 
low Ocher)  (30). 

2Fe2O3 
+3H20. 

Dull. 

Yellow. 

Yellow. 

G.  3.5  to  4. 

Orpiment  (14). 

Compare  Realgar. 
[Comp.  also  S.  T.  n, 

As2S3. 

Resinous 
to  pearly. 

Yellow. 

Yellow. 

23,  24,25.  26,  29,  49.] 

Streak  bright 
yellow  to 
orange. 

Zincite  (21). 

ZnO. 

Sub- 
adamantine. 

Red  to 
orange. 

Orange. 

Streak  pale 

Wulfenite  (41). 

PbMoO  . 

Resinous  to 
adamantine. 

Yellow. 

Yellowish 
white. 

yellow. 

1 

. 

G.  6  to  7. 

Vanadinite  (37). 

Compare    Pyromor- 
phite  and  Mimetite. 

+PbCl2. 

Resinous 
to  dull. 

Red  and 
yellow  to 
brown. 

Yellowish 
white. 

g 

! 

Streak  deep 
yellow* 
G.  3  to  4. 

Siderite  (45). 

FeCo3. 

Vitreous 
to  dull. 

Gray  to 
dark  brown. 

Gray  to 
yellow  and 
brown. 

^O 

Become 

y 

magnetic  on 
charcoal  B.  B. 

Limonite  (30). 

Compare  Gothite. 
[Compare  also  S.  T. 

2Fe203 
+3H20. 

Submetallic 
to  dull. 

Dark  brown 
to  yellow. 

Yellow. 

n,  24,  29,  44,  55.] 

Streak  light 

yellow  to 
brown. 

Sphalerite  (8). 

ZnS. 

Resinous. 

Yellow 
to  brown. 

Light 
yellow  to 

G.  about  4. 

brown. 

Streak  bright 
yellow  to 
orange. 

Zincite  (21). 

ZnO. 

Sub- 
adamantine. 

Red  to 

orange. 

Orange. 

Siderite  (45). 

FeC03. 

Vitreous 
to  dull. 

Gray  to 
dark  brown. 

Gray  to 
yellow  and 

Streak  deep 

brown. 

^3 

yellow. 

S 

G.  3  to  4.5 
Become 

Limonite  (30). 

2Fe2O3 
+3H20. 

Submetallic 
to  dull. 

Brown  to 
black. 

Yellow. 

CO 

magnetic  on 

charcoal  B.  B. 

Gothite  (29). 

Fe203 
+H20. 

Adamantine 
to  dull. 

Brown  to 
black. 

Yellow. 

Streak  light 
yellow  to 
brown. 
G.  about  4. 

Sphalerite  (8). 

ZnS. 

Resinous. 

Yellow 
to  brown. 

Light 
yellow  to 
brown. 

METALLIC     LUSTER. 


57 


H. 

Tenacity 

G. 

Form. 

Cleavage. 

Other 
Properties. 

Confirmatory  Chemical  Tests. 

i-5- 

2-5 

Brittle. 

2. 

IV.  Pyramidal 
crystals,  often 
massive 

Imperfect. 
Fracture 
conchoidal 

Translucent 
Electric  by 
friction 

Burns  with  a  blue  flame  and  sul- 
phurous odor. 

i. 

Plastic  to 
earthy 

2.6 

IV.  Usually 
compact  or 
clayey 

Earthy. 

Opaque. 

B.  B.  infusible  ;  insoluble  ;  water  in 
closed  tube;  blue  color  with  co- 
balt solution. 

i- 

2-5 

Earthy. 

3-6- 
4- 

Compact. 

Earthy. 

Opaque. 

B.  B.  infusible;  becomes  black  and 
magnetic  on  charcoal;  water  in 
closed  tube;  soluble  in  HC1. 

i-5- 

2. 

Sub- 
sectile 

3-5 

IV.  Usually 
foliated, 
botryoidal  or 
massive 

Brachypina- 
coidal, 
perfect 

Translucent. 

Volatilizes,  and  gives  reactions  for 
arsenic  and  sulphur. 

4- 
4-5 

Brittle. 

54- 
5-7 

III.  Lamellar, 
also  massive 

Basal,  " 
perfect 

Usually 
opaque 

B.  B.  infusible;  zinc  oxide  coating 
with  soda  on  charcoal  in  R.  F.; 
soluble  in  acid. 

3- 

Brittle. 

6.7- 

7- 

II.  Very  thin, 
square,  tabular 
crystals. 

Octahedral, 
distinct 

Translucent. 

B.  B.  fuses  readily  (1.5);  and  yields 
lead  with  soda  on  charcoal. 

3- 

Brittle. 

6.7- 
7.2 

III.    Small  pris- 
matic crystals, 
usually 
incrusting. 

None. 

Translucent 
to  opaque 

B.  B.  fuses  readily;  yields  lead  with 
soda  on  charcoal  ;  and  reacts  for 
chlorine  with  copper  oxide  and 
SPh. 

3-5- 
4- 

Brittle. 

3-8 

III.  Rhombo- 
hedral,  also 
massive  and 
compact. 

Rhombohe- 
dral,  perfect. 

Translucent 
to  opaque. 

B.  B.  infusible;  blackens  and  be- 
comes magnetic;  effervesces  in 
hot  acid,  evolving  COg. 

3-4- 

3-5- 
4- 

4- 
4-5 

Brittle. 

3-6- 
4- 

Compact, 
fibrous  and 
botryoidal. 

Fracture 
uneven, 
splintery,etc. 

Opaque. 

B.  B.  infusible;  water  in  closed  tube; 
becomes  black  and  magnetic  on 
charcoal;  soluble  in  HC1. 

Brittle. 

3-9- 
4.1 

I.  Tetrahedral, 
usually  massive 
or  granular. 

Dodecahe- 
dral,  perfect. 

Translucent 
to  opaque. 

B.  B.  infusible;  reactions  for  sul- 
phur; zinc  oxide  coating  with 
soda  on  charcoal;  effervesces  in 
hot  acid,  evolving  H2S. 

Brittle. 

54- 
5-7 

III.  Lamellar, 
also  massive. 

Basal, 
perfect 

Usually 
opaque. 

B.  B.  infusible;  zinc  oxide  coating 
with  soda  on  charcoal;  soluble  in 
acid. 

3-5- 
4- 

Brittle. 

3-8 

III.  Rhombo- 
hedral,  also 
massive    and 
compact. 

Rhombohe- 
dral,  perfect. 

Translucent 
to  opaque. 

B.  B.  infusible;  blackens  and  be- 
comes magnetic;  effervesces  in 
hot  acid,  evolving  CO2. 

5- 
5-5 

Brittle. 

3-6- 
4- 

Compact, 
botryoidal, 
fibrous,  etc. 

Fracture 
uneven, 
splintery,etc. 

Opaque. 

B.  B.  infusible;  water  in  closed 
tube;  becomes  black  and  mag- 
netic on  charcoal;  soluble  in  HCl. 

5- 
5-5 

Brittle. 

4~ 
44 

IV.  Usually 
massive,  fibrous 
or  botryoidal. 

Prismatic, 
perfect. 

Opaque. 

Like  limonite. 

3-5- 
4- 

Brittle. 

3-9 
..i 

I.  Tetrahedral, 
usually  massive 
or  granular. 

Dodecahe- 
dral,  perfect. 

Translucent 
to  opaque. 

3,  B.  infusible;     reactions   for   sul- 
phur;    zinc    oxide   coating   with 
soda  on  charcoal;    effervesces  in 
hot  acid,  evolving  H^S. 

B.     MINERALS    WITHOUT 


Analytical     Key. 

Species. 

Composition 

Luster. 

Color. 

Streak. 

£   | 

I 

Compact. 

Quartz  (Jasper) 
(33)- 

SiO 
+Fe203. 

Nearly  dull. 

Brown 
to  yellow. 

Light 
yellow. 

^j     "§5 

r 

Jf 

1 

Crystalline. 

Quartz   (Ferrugi- 
nous Quartz)  (33). 

SiO2 
+Fe203. 

Vitreous  to 
nearly  dull. 

Brown 
to  yellow. 

Light 
yellow. 

Asphaltum  (84). 

C,H,O,  etc. 

Resinous 
to  dull. 

Brownish 
black  to 
black. 

Dark  brown 
to  black. 

G.  below  2. 

! 

Combustible. 

Mineral  Coal 

(84)- 

C,H,O,  etc. 

Resinous  to 
submetallic. 

Brownish 
black  to 
black. 

Dark  brown 
to  black. 

^ 

G.  below  3. 

Kaolinite  (car- 
bonaceous)  (79). 

Al2Si2O7 
+2H2O. 

Dull. 

Dark  gray 
or  brown 
to  black. 

Dark  gray 
or  brown 
to  black. 

G.  above  3. 

Wad  (32). 
[Compare 

MnO2+ 
H2O. 

Dull. 

Black. 

Black. 

S,  T.  10,  99,  loo.] 

G.  below  2. 

Mineral  Coal 

(84). 

C,H,O,  etc. 

Resinous  to 
submetallic. 

Brownish 
black  to 
black. 

Dark  brown 
to  black. 

§ 

i 

G.  below  4.$ 

Wad  (32). 

MnO2+ 
H2O. 

Dull. 

Black. 

Black. 

1 

G.  above  $.$ 

Melaconite  (22). 

CuO. 

Metallic 
to  dull. 

Black. 

Black. 

N 

G.  not  above  5. 

Psilomelane 

MnO2+ 
H20. 

Submetallic. 

Black. 

Brownish 

black. 

Compare 

crystallization 

Menaccanite 

(25). 

(FeTi)203. 

Submetallic. 

Black. 

Brownish 
black. 

i 

Samarskite(35). 

Complex 
columbate. 

Submetallic, 
shining. 

Black. 

Reddish 
brown  to 
brownish 

G.  above  $.$ 

gray. 

Compare  luster. 

Melaconite  (22). 

CuO. 

Metallic 
to  dull. 

Black. 

Black. 

G.  above  7. 

Wolframite 

(40. 

Compare  Colunibite. 

(FeMn) 
WO4. 

Submetallic. 

Brownish 
black. 

Dark 
reddish 
brown  to 

[Compare  also  S.T. 

black. 

3i,  54,  89-] 

Columbite- 

i^ 

Crystalline. 
G.  above  c. 

tantalite  (35). 

Compare  Psilome- 

FeCb2O6. 

Submetallic. 

Black. 

Dark  red 
to  black. 

•  te 

lane,  Menaccanite 

MI 

and  Samarskite  . 

METALLIC     LUSTER. 


59 


H. 

Tenacity 

G. 

Form. 

Cleavage. 

Other 
Properties. 

Confirmatory  Chemical  Tests. 

7- 

Brittle. 

2.6 

III.  Compact. 

None. 

Translucent 
to  opaque. 

B.  B.  infusible;   insoluble. 

7- 

Brittle. 

2.6 

!7s 

i- 

1.8 

III.  Crystals,  but 
often  massive. 

None. 

Translucent 
to  opaque. 

B.  B.  infusible;  insoluble. 

1-5 

i- 

2-5 

Brittle  to 
flexible. 

Brittle  to 
earthy. 

Amorphous. 

Amorphous, 
often  laminated. 

Conchoidal. 

Even  or 
conchoidal. 

Opaque. 
Opaque. 

B.  B.  fuses  and  burns  with  flame. 
B.  B.  infusible;   but  readily  ignited. 

i. 

Plastic  to 
earthy. 

2.6 

IV.  Usually 
compact 
or  earthy. 

Earthy. 

Opaque. 

B.  B.  infusible,  whitens;  insoluble; 
water  in  closed  tube. 

i- 

2-5 

Earthy  to 
brittle. 

3- 

4-2 

Amorphous. 

Earthy. 

Opaque. 

B.  B.  infusible;  water  in  closed  tube; 
amethystine  bead  with  borax; 
evolves  chlorine  with  HC1. 

2-5 

Brittle. 

1.8 

Amorphous, 
often  laminated. 

Even  or 
conchoidal. 

Opaque. 

B.  B.  infusible;   but  readily  ignited. 

2-5- 
4- 

Brittle  to 
earthy. 

3- 
4.2 

5-8- 
6.25 

Amorphous. 

Uneven 
to  earthy. 

Opaque. 

B.  B.  infusible;  waterin  closed  tube; 
amethystine  bead  with  borax; 
evolves  chlorine  with  HC1. 

3-4- 

Brittle  to 
earthy. 

IV.  Usually 
massive  or 
earthy. 

Uneven  or 
earthy. 

Opaque. 

B.  B.  infusible  ;  green  flame;  cop- 
per with  soda  on  charcoal  ;  green 
solution  with  nitric  acid. 

5-6. 

5-6. 

Brittle. 
Brittle. 

3-7- 
4-7 

4-5- 
5- 

Compact  or 
botryoidal. 

III.  Often 
tabular, 
also  massive. 

Even  or 
conchoidal. 

None. 

Opaque. 

Opaque. 
Often  slight- 
ly magnetic. 

B.  B.  infusible;  amethystine  bead 
with  borax;  water  in  closed  tube; 
evolves  chlorine  with  HC1. 

B.  B.  infusible;  reactions  for  iron. 

5-6. 
3-4- 

Brittle. 

Brittle  to 
earthy. 

5-6- 
5.8 

5.8- 
6.25 

IV.  Also 
massive. 

IV.  Usually 
massive  or 
earthy. 

Uneven  or 
conchoidal. 

Uneven  or 
earthy. 

Opaque. 
Opaque. 

B.  B.  fusible  with  difficulty  (4.5); 
emerald-green  bead  with  SPh; 
green  bead  with  soda. 

B.  B.  infusible  ;  green  flame;  cop- 
per with  soda  on  charcoal;  green 
solution  with  nitric  acid. 

5- 
.5-5 

Brittle. 

7.2- 

7-5 

V.  Also 
lamellar  or 
massive. 

Prismatic, 
perfect. 

Opaque. 

B.  B.  fuses  (3)  to  a  magnetic  glob- 
ule ;  reactions  for  manganese. 

6. 

Brittle. 

5-5- 
7-3 

IV.  Usually 
in  crystals. 

Prismatic. 

Opaque. 

B.  B.  infusible;   insoluble. 

6o 


B.     MINERALS     WITHOUT 


Analytical  Key. 

Species. 

Composition 

Luster. 

Color. 

Streak. 

I 

55 
k 

o 

1 

a 

I 

! 

Streak  green. 
Earthy. 

Glauconite  (78) 

rA!FeK)Si 
X  03+H20. 

Dull. 

Dark  green. 

Lighter 
green. 

Color  and  streak 
green. 
Compare  by 
transmitted 
light. 

Prochlorite(77). 
Clinochlore  (  77)  . 

(FeMg)23 
+2oH2O. 

Al2Mg5Si3 
OK+4H2O. 

Pearly 
to  dull. 

Pearly. 

Dark  green. 
Deep  green. 

Lighter 
green. 

Greenish 
white. 

Streak  blue. 

Vivianite  (38). 
[Compare  S.T.  no,  23, 
24,25,48,59.66.] 

Fe3P208 
+8H2O. 

Vitreous 
to  pearly 
or  dull. 

Blue  to 
green. 

Bluish. 

i 

Color  and  streak 
green. 
Not  micaceous. 

Atacamite  (19). 
Malachite  (47). 

Compare 
Chrysocolla. 

CuCl2-h 
3li2CuO2. 

CuoCO4 
-  +H20. 

Adamantine 
to  vitreous. 

Adamantine, 
silky  or  dull. 

Green. 
Green. 

Apple  - 
green. 

Paler  green. 

Color  black. 
Streak  green. 
Micaceous. 

Lepidomelane 

(75)- 

Compare 
Clinochlore. 

(AlFeK)2 
Si04. 

Adamantine 
to  pearly. 

Black. 

Grayish 
green. 

Color  and  streak 
blue. 

Azurite  (47). 
Compare 
Chrysocolla. 
^Compare  S.T.  24,  43, 
45,  58,  71,81,97.] 

Cu3C2O7 
+H20. 

Vitreous 
to  dull. 

Blue. 

Paler  blue. 

1 

Color  and  streak 
green. 
Compare  G.  and 
diaphaneity. 

Malachite  (47). 
Dioptase  (56). 

CuoCO4 
"   +H20. 

CuSiO3 
+H20. 

Adamantine, 
silky  or  dull. 

Vitreous. 

Green. 

Emerald- 
green. 

Paler  green. 
Green. 

Color  black. 
Streak  greenish. 
Compare  cleav- 
age angle. 

Pyroxene 

(Augite)  (50). 

Amphibole 

(Hornblende) 
(50. 

(CaMgAl 
Fe)Si03. 

(CaMgAl 
Fe)SiO3. 

Vitreous. 
Vitreous. 

Greenish 
black. 

Greenish 
black. 

Grayish 
green. 

Grayish 
green. 

Color  and  streak 
blue. 
Compare 
G.  and  H. 

Azurite  (47). 

Lazurite  (54). 
Compare  S  T. 
54,81,97.] 

Cu3C2O7 
-r-H2O. 

(CaNaAl)2 
SiO4. 

Vitreous 
to  dull. 

Vitreous. 

Blue. 
Blue. 

Paler  blue. 
Blue. 

fl 

Streak  bluish 
or  greenish. 

Turquois  (39). 

Compare    Laz- 
urite,  Pyroxene, 
and  Amphibole. 
[CompareS.  T.  80.] 

Al4P2Oii 
+5H20. 

Waxy 
to  dull. 

Sky-blue  to 
apple-green 
or  greenish 
gray. 

Bluish  to 
greenish 
white. 

METALLIC     LUSTER. 


61 


H. 

Tenacity 

G. 

Form. 

Cleavage. 

Other 
Properties. 

Confirmatory  Chemical  Tests. 

1-2. 

Granular 
and 
earthy. 

2.2- 
2.4 

Amorphous. 

Earthy. 

Opaque. 

Water  in    closed  tube;   B.  B.  fuses 
(3)  to  a  dark  magnetic  glass. 

1-2. 

Some- 
what 
sectile. 

2.8- 

3- 

V.  Usually 
finely  foliated 
to  massive. 

Basal, 
perfect. 

Translucent 
to  opaque. 

B.  B  fuses  with  difficulty;   water  in 
closed  lube. 

Flexible 

V.  Foliated  or 

Basal, 

Emerald- 

2- 
2-5 

and 
sectile. 

2-7 

micaceous  to 
massive. 

highly 
perfect. 

green  by 
transmitted 
light. 

Like  prochlorite. 

2. 

Sectile  to 
earthy. 

2.6 

V.  Crystals, 
but  often 
massive  or 
earthy. 

Clinopina- 
coidal, 
perfect. 

Translucent 
to  opaque. 

B.  B.  fuses  easily  (1.5)  to  a  mag- 
netic  globule;     water   in   closed 
tube;   soluble  in  acid. 

3- 
3-5 

Brittle. 

3-75 

IV.  Crystalline 
crusts,  also 
massive. 

Brachy- 
pinacoidal, 
perfect. 

Transparent 
to  opaque. 

B.  B.  fuses  with  a  blue  flame;   yields 
metallic  copper  on  charcoal;  water 
in  closed  tube. 

V.  Crystals  rare, 

B.  B.  fuses  easily  (2),  coloring  flame 

3.5- 

Brittle 

3-9- 

often  botryoidal, 

Basal, 

Translucent 

green;  yields  copper  on  charcoal; 

4- 

4- 

fibrous  or 

perfect. 

to  opaque. 

water  in  closed  tube;    effervesces 

earthv 

with  acid. 

Sectile  to 

3- 

V.  Foliated  or 

Basal, 

Translucent 

B.  B.  fuses  easily  to  a  magnetic  glob- 

3- 

brittle. 

3-2 

micaceous. 

perfect. 

to  opaque. 

ule;   decomposed  by  HC1. 

V.  Crystals,  also 

B.  B.  fuses  easily  ^2),  coloring  flame 

3-5- 
4- 

Brittle. 

3-8 

globular, 
massive  or 

Clinodome, 
perfect. 

Translucent 
to  opaque. 

green  ;  yields  copper  on  charcoal; 
water  in  closed  tube;    effervesces 

earthy. 

with  acid. 

V.  Crystals  rare. 

B.  B.  fuses  easily  (2),  coloring  flame 

3-5- 
4- 

Brittle. 

3-9- 
4- 

often  botryoidal, 
fibrous  or 

Basal, 
perfect. 

Translucent 
to  opaque. 

green  ;  yields  copper  on  charcoal; 
water  in  closed  tube;    effervesces 

earthy. 

with  acid. 

S-" 

Brittle. 

3-3 

III.  Rhombohe- 
dral  crystals. 

Rhombohe- 
dral,  perfect. 

Transparent 
to 
translucent. 

B.  B.  infusible;  green  flame;  black- 
ens  and   yields  water  in    closed 
tube;  copper  on  charcoal;  gelat- 
inizes with  HC1. 

5-6. 

Brittle. 

3-2- 
3-6 

V.  Prismatic 
crystals,  also 

Prismatic, 
perfect. 
Angles 

Translucent 
to  opaque. 

B.  B.  fusible  (2.5-5)  ;  insoluble. 

87°  5'. 

V.  Prismatic 

Prismatic, 

5-6. 

Brittle. 

2-9- 
3-4 

crystals,  also 
massive,  bladed, 

perfect. 
Angles 

Translucent 
to  opaque. 

Like  pyroxene. 

or  fibrous. 

I24C  II'. 

V.  Crystals,  also 

B.  B.  fuses  easily  (2),  coloring  flame 

3-5- 

4- 

Brittle. 

3-8 

globular, 
massive  or 

Clinodome, 
perfect. 

Translucent 
to  opaque. 

green,  and  yields  copper  on  char- 
coal; water  in  closeol  tube;    effer- 

earthy. 

vesces  with  acid. 

5- 
5-5 

Brittle. 

2.4 

I.  Usually 
compact. 

None. 
Fracture 
uneven. 

Opaque. 

B.  B.  fusible  (3);    gelatinizes  with 
HC1. 

Amorphous, 

6. 

Brittle. 

2.6- 

2.8 

compact,  in- 
crusting,  seams 

Fracture 
conchoidal. 

Opaque. 

B.  B  .  infusible  ;  water  in  closed  tube  ; 
soluble  in  acid. 

and  grains. 

62 


B.     MINERALS  WITHOUT 


Analytical    Key. 

Species. 

Composition 

Luster. 

Color. 

Streak. 

Biotite  (75). 

(HK2MgFe 
Al)2SiO4 

Pearly, 
splendent 

Black  to 
deep  green 
and  brown 

White. 

Micaceous. 

Folias  highly 
elastic. 

Phlogopite  (75) 

(HKMg 
Al)2SiO4 

Pearly  to 
submetallic 

Yellowish 
brown 

White. 

Compare  color. 

Colorless, 

Muscovite  (75). 

AlKSiO4. 

Pearly. 

gray,  brown, 

White. 

Compare  Lepidolite. 

green,  etc. 

Micaceous. 
Folise  somewhat 
elastic. 

Clinochlore(77). 
Compare     Talc    anc 
Prochlorite. 
[Compare  also  S.  T. 

Mg5Al2Si 
014+4H20 

Pearly. 

Deep  green. 

White  or 
greenish 
white. 

Color  green. 

93-  94,  95-. 

Fibrous  nodules. 
Very  light. 

Ulexite  (40). 

NaCaB5O9 
+5H20 

Silky  to  dull 

White. 

White. 

Fibrous. 
Greenish. 
Water  in 

Serpentine 

(Chrysotile)  (78). 
Compare  Amphibole 

Mg3Si2O7 

4-2H2o 

Silky. 

Green  to 
yellowish 

White. 

closed  tube. 

(Asbestus). 

green. 

. 

Fibrous. 

e 
4 
fc 

§ 

Little  or  no 
water  in  closed 
tube. 

Amphibole 
(Asbestus)  (51). 

(CaMg) 
Si03 

Silky  to  dull. 

White,  gray, 
or  greenish. 

White. 

<» 
32 

!•££ 

SQ 

i. 

Fiorous. 
Much  water  in 
closed  tube. 

Gypsum 

(Satin  Spar)  (43). 

CaSO4 
+2H2O. 

Pearly  to 
silky  and 
dull. 

White,  gray, 
brown,  etc. 

White. 

1 

E 

»*i 

Halite  (17) 

White  to 

SQ 

Taste  like  salt. 

(Common  Salt). 

NaCl. 

Vitreous. 

gray,  brown, 

White. 

Compare 

£ 

S.  T.  22,60,61.] 

Kalinite  (44) 

Taste  like  alum. 

(Native  Alum). 

Compare 

K2A12S4016 
+24H2O. 

Vitreous 
to  dull. 

White. 

White. 

S.  T.  62,  63,  64.] 

Taste  feebly 
alkaline. 

Borax  (40). 
Compare 

Na2B4O7 
+  ioH2O. 

Vitreous  to 
resinous. 

White. 

White. 

S.  T.  50,  56,  68.] 

Sulphur-yellow. 

Sulphur  (4). 

S. 

Resinous. 

to  brown. 

White. 

Very  dark  green, 
foliated  or 
scaly. 

Prochlorite  (77). 

(FeMg) 
Al14Si13O70 
4-2oH2O. 

Pearly 
to  dull. 

Dark  green. 

Greenish 
gray. 

Green  or  bluish 

Garnierite  (78). 

(Ni,Mg) 
Si03+H2O. 

Dull  to 
resinous. 

3right  apple- 
green  to 
whitish. 

White. 

green. 

Perfectly  com- 

)act  or  wax-like. 

Chrysocolla 

(80). 

CuSiOo 
-f-2H20. 

Vitreous 
to  dull. 

Jluish  green 
to  blue. 

Whitish. 

METALLIC  LUSTER. 


H. 

2-5- 
3- 

2-5- 
3- 

2- 
2-5 

Tenacity 

G. 

Form. 

Cleavage. 

Other 
Properties. 

Confirmatory  Chemical  Tests. 

Elastic 
and 
sectile. 

Elastic 
and 
sectile. 

Elastic 
and 
sectile. 

2.7- 
3-i 

2.8 

2-75 
-3- 

2.7 
1.65 

2.2- 

2.6 

V.  Tabular  or 
foliated. 

V.  Tabular  or 
foliated. 

V.  Usually  tab- 
ular, foliated, 
or  lamellar. 

Basal,  very 
perfect. 

Basal,  very 
perfect. 

Basal,  highly 
perfect. 

Transparent 
to  opaque. 

Transparent 
to 
translucent. 

Transparent 
to 
translucent. 

B.  B.  fuses  with  difficulty;  decom- 
posed by  H  SO4;  reactions  for 
iron;  little  water  in  closed  tube. 

B.  B.  fuses  with  difficulty;  decom- 
posed by  H2SO4;  little  water  in 
closed  tube. 

B.  B.  infusible;  insoluble;  little 
water  in  closed  tube. 

2- 
2-5 

Flexible 
and 
sectile. 

V.  Foliated  or 
micaceous. 

Basal,  highly 
perfect. 

Emerald- 
green  by 
transmitted 
light. 

B.  B.  fuses  with  difficulty;  much 
water  in  closed  tube;  decomposed 
by  H2SO4. 

I. 

Sectile. 

Rounded  nod- 
ules of  loose 
texture. 

Finely 
fibrous. 

Opaque. 

B.  B.  fuses  readily  (i)  to  a  clear 
glass,  coloring  flame  yellow;  with 
H2SO4  the  flame  is  green;  much 
water  in  closed  tube. 

2-5- 
4- 

Flexible 
and 
sectile. 

Fibrous  veins 
and  massive. 

Delicately 
fibrous. 

Translucent. 

B.  B.  infusible  ;  water  in  closed  tube; 
decomposed  by  HC1. 

Very 

soft 
to  5. 

Flexible 
and 

sectile. 

2.9- 

3-i 

2-3 

V.  Finely 
fibrous. 

Fibrous, 
perfect. 

Opaque  to 
semi-trans- 
lucent. 

B.  B.  fusible  (2.5-5)  >  insoluble. 

i-5- 

2. 

Sectile 
to  brittle. 

V.  Usually 
foliated, 
massive,  or 
fibrous. 

Clinopina- 
coidal, 
perfect. 

Transparent 
to  opaque. 

B.  B.  fuses  (3);  water  in  closed 
tube;  sulphur  reaction  with  soda 
on  charcoal. 

2-5 

Very 
brittle. 

2.1- 

2.6 

I.  Cubes,  also 
massive. 

Cubic, 
perfect. 

Transparent 
to 
translucent. 
Saline  taste. 

B.  B.  fuses  easily  Coloring  flame  deep 
yellow;  soluble  in  water. 

2-5 

Brittle  or 
friable. 

'•75 

I.  Massive  or 
mealy  crusts. 

Crumbles 
easily. 

Transparent 
to  opaque. 
Astringent 

taste. 

Fuses  in  its  water  of  crystallization, 
forming  an  infusible,  spongy  mass; 
intense  blue  with  cobalt  solution 
after  fusion;  soluble  in  water. 

2- 
2-5 

l-S- 

2-5 

Very 
brittle. 

!-7 

V.  Usually 
crystallized, 
or  massive. 

Pinacoidal, 
perfect. 

Translucent 
to  opaque. 
Taste  feebly 
alkaline. 

B.-B.  puffs  up  and  fuses  easily  to  a 
clear  glass,  coloring  flame  yellow; 
soluble  in  water;  water  in  closed 
tube. 

Very 
brittle. 

2. 

IV.  Pyramidal 
crystals, 
also  massive. 

Imperfect. 
Fracture 
conchoidal. 

Translucent. 
Electric  by 
friction. 

Burns  with  a  blue  flame  and  sulphu- 
rous odor. 

1-2. 

Very 

soft. 

2-4. 

Some- 
what 
sectile. 

2.8- 

3- 

V.  Usually 
finely  foliated. 

Basal, 
perfect. 

Translucent 
to  opaque. 

B.  B.  fuses  with  difficulty;  water  in 
closed  tube. 

Friable. 

Brittle  to 
sectile. 

2.8 

2- 

2.2 

Amorphous. 

Compact, 
sometimes 
botryoidal. 

None; 
crumbles 
easily. 

None. 

Translucent 
to  opaque. 

Opaque. 

B.  B.  infusible;  much  water  in  closed 
tube;  decomposed  by  HC1  with- 
out gelatinizing. 

B.  B.  infusible;   colors  flame  green; 
yields  water;    copper   with   soda 
on  charcoal. 

B.     MINERALS     WITHOU1 


Analytical  Key. 

Species. 

Composition 

Luster. 

Color. 

Streak. 

Succinite 

^ike  resin. 

jr.    I. 

k  Amber)  and 
Copalite  (84). 

C,H,O,  etc. 

Resinous. 

Yellow  and 
brown  to 

\Vhite. 

[Compare 

white. 

S.  T.  99,  zoo.] 

Highly  greasy 
feel, 
^oliated  or 

Talc   (78). 

Mg3Si4On 
+H20. 

Pearly 
to  dull. 

Green  to 
white,  gray, 
etc 

White. 

compact. 

Not  earthy  or 
clay-like. 

Pyrophyllite 

(79). 

Al2Si4On 

Dull  to 

White,  gray, 

White 

Compare  water 

Compare  Sepiolite 

+H20. 

pearly. 

green,  etc. 

in  tube. 

and  Halloysite. 

Compact, 
floats  on  water 
when  dry. 

Sepiolite  (78). 

Mg2Si308 
+2H2O. 

Dull. 

White 
to  gray. 

White. 

Earthy  or 

chalky. 
Effervesces 

Calcite  (Chalk) 

(45). 

CaCO8. 

Dull. 

White. 

White. 

in  acid. 

Compare  S.  T.  67.] 

White,  gray, 

sc 

Earthy  or 
clav-like. 

Kaolinite  (79). 

Al2Si207 
+2H2O. 

Dull  to 
pearly. 

yellow,  red, 
blue,  green, 
etc 

Like  color. 

e 

, 

Becomes  plastic 

i 

in  water. 
Compare  color. 

Montmorillon- 

ite  (79). 

Al  Si4On 
-|-nH20. 

Dull. 

White,  red, 
blue  or 

Like  color. 

t 

o 

^Compare  S.  T.  52.] 

green. 

o 

0 
( 

Compact,  or  like 
hard  clay. 
Not  plastic  in 

Halloysite  (79). 

^+nH2O. 

Waxy 
to  dull. 

White,  gray, 
greenish, 
etc. 

Like  color. 

S 

SQ 

water 

1 

1 

Earthy. 
Not  plastic. 
Disting.  with 

Opal  (Tripolite  or 
diatomaceouS 
earth)  (34). 

SiO2H-H2O. 

Dull. 

White  to 
yellowish 
gray,  etc 

Like  color. 

8§ 

microscope- 
diatoms  present 
or  absent 

Opal  (Geyserite 
or  siliceous  tufa) 
(34). 

Si02-f-H20. 

Du  1 

White 
to  gray. 

White 
to  gray. 

Coarse,  earthy 

or  mealy 

Laumontite(  dis- 

CaAloSi4O12 

Vitreous 

White 

White 

powder 

integrated)  (70). 

+4H20. 

to  dull. 

to  red 

Not  plastic. 

Compact  or 
wax-like 
Not  sectile. 

G.  2. 

Deweylite  (78). 

+6H2O. 

Greasy. 

Yellow  to 
gray  and 
greenish 

White. 

Compact  or  wax- 
like.     Sectile. 
G.  5.5  when 

Cerargyrite  (17) 

AgCl. 

Resinous 
to  dull. 

Gray  to 
brown 

Gray  to 
white, 
shining. 

pure 

One  perfect 
cleavage  or 

Gypsum  (43). 

CaS04 
-r-2H2O. 

Pearly  to 
silky  and 
dull. 

White,  gray 
brown,  etc 

White. 

massive 

Much  water  in 
closed  tube 

Brucite  (31). 

[Compare 

MgO 
+H20. 

Pearly. 

White  to 
greenish 

White. 

S.T.32,33.1 

METALLIC     LUSTER. 


H.     Tenacity 

G. 

Form. 

Cleavage.            Other                Confirmatory  Chemical  Tests. 
Properties. 

2- 
2-5 

Brittle. 

I. 

Amorphous. 

None. 

Transparent 
to 
translucent. 

Fuses  readily  and  burns  with  a  yel- 
low flame. 

"s 

Sectile 
and 
inelastic. 

2.7- 
2.8 

IV.  Usually 
:oliated,  some- 
times compact. 

Basal, 
perfect. 

Greasy  feel. 
Translucent. 

B.  B.  infusible;    insoluble;   little  or 
no  water  in  closed  tube  at  a  red 
heat. 

1-2. 

Some- 
what 

sectile. 

2.8- 

2.9 

V.  Usually 
compact,  some- 
times foliated. 

Basal, 
perfect. 

Greasy  feel. 
Translucent 
to  opaque. 

B.  B.    fuses   with    difficulty;     yields 
water  at  a  red  heat;    blue  color 
with  cobalt  solution. 

Some- 

Very 

B.  B.    infusible;     water    in    closed 

2- 

what 

lignt 

Compact. 

None. 

Opaque. 

tube;  pink  color  with  cobalt  solu- 

2.3 

sectile. 

to  2. 

tion;  gelatinizes  with  HC1. 

B.  B.  infusible;    soluble  with  effer- 

°-5~ 

Earthy. 

2.6 

III.  Compact. 

Earthy. 

Opaque. 

vescence;    alkaline  reaction  after 

'•5 

heating. 

2-5 

Plastic 

or 
earthy. 

2.4- 
2.6 

V.  Usually  com- 
pact or  clayey. 
Crystals 
microscopic. 

Basal, 
perfect. 
Finely  scaly. 

Translucent 
to  opaque. 
Argillaceous 
odor. 

B.  B.  infusible;   insoluble;   water  in 
closed  tube;  blue  color  with  cobalt 
solution. 

Very 

soft. 

Tender 
to 

Lig't 

Massive, 
clay-like. 

Earthy. 

Opaque. 
Unctuous. 

B.  B.  infusible;  much  water  in  closed 
tube. 

1-2. 

Like 
hard 
clay. 

2- 
2.2 

Massive, 
clay-like. 

Earthy  to 
conchoidal. 

Translucent 
to  opaque. 

B.  B.  infusible;  much  water  in  closed 
tube  ;  fine  blue  color  with  cobalt 
solution;   decomposed  by  acid. 

Very 

B.  B.  infusible;  water  in  closed  tube; 

°-5 

1.8 

Earthy. 

h&ht 

Amorphous. 

Earthy. 

Opaque. 

insoluble  in  acid;  soluble  in  caus- 

—1.5 

tic  potash. 

-5. 

Earthy 
to 
brittle. 

2. 

Amorphous, 
often  tufaceous. 

Earthy. 

Opaque. 

B.  B.  infusible;  water  in  closed  tube; 
insoluble  in  acid;  soluble  in  caustic 
potash. 

Brittle 

2.25 

V.  Also 

Opaque  and 

B.  B.  fuses  easily  with  intumescence  ; 

3-5 

to 

to 

columnar 

Perfect. 

pulverulent 

yields  water  in  closed  tube;  gelat- 

4- 

friable. 

2-35 

and  massive. 

on  exposure. 

inizes  with  HC1. 

2- 

3-5 

Brittle. 

2- 
2.2 

Compact,  waxy. 

None. 

Translucent. 

B.  B.  infusible;  yields  much  water  in 
closed  tube;  decomposed  by  HC1. 

i- 

Waxy 
and 
sectile. 

5-5 

I.  Usually 
compact. 

None. 

Transparent 
to  opaque. 

B.  B.  fuses  very  readily  (i);    silver 
on  charcoal;    reacts  for  chlorine 
with  CuO  and  SPh. 

2. 

Sectile 
to 
brittle. 

2-3 

V.  Usually 
foliated, 
massive  or 
fibrous. 

Clinopina- 
coiclal, 
perfect. 

Transparent 
to  opaque. 

B.  B.    fuses    (3)  ;     water   in    closed 
tube;   sulphur  reaction  with  soda 
on  charcoal. 

B.  B.  infusible;  alkaline  reaction  af- 

2-5 

Flexible 
and 

2.4 

III.  Usually 
foliated. 

Basal, 
perfect. 

Translucent. 

ter  heating;  pink  color  with  cobalt 
solution;    water   in    closed  tube; 

soluble  in  acid. 

66 


B.     MINERALS     WITHOUT 


Analytical     Key. 

Species.             Composition        Luster. 

Color. 

Streak. 

Black,  deep 

green  or      Biotite  (75).          (HKMgFe 
brown,   even;c0mpare                           Al)2biO4. 
in  thin  foliae.             Lepidomelane. 

Pearly, 
splendent. 

deep  green 
and  brown. 

White. 

1 

,     (HKA1) 
Muscovite  (75).  v            J^Q 

Pearly. 

White, 
brown,  pale 

White. 

^ 

green,  etc. 

.Sf 

Not  black  in 

Yellowish 

% 

thin  foliae. 
Compare 

Al)2SiO4. 

Pearly  to 
submetallic. 

brown  to 
brownish 

White. 

{£ 

colors. 

red. 

o 

8 

••  ./. 

Lepidolite  (75).  (HLiKAl)2 

Pearly. 

Rose-red 
and  violet 

White. 

to  white. 

1 

Black,  even 
in  thin  foliae. 

Lepidomelane 
(75). 

(HKFeAl)2 
Si04. 

Adamantine 
to  pearly. 

Black. 

Grayish 
green. 

ss 

tn 

Red,  pink, 
or  reddish 

Margarite  (76). 

CaAl4Si2Ou 
+H20. 

Pearly. 

Reddish 
white  to 

White. 

,0 

gray. 

gray. 

y.  —  Contii 

Folue  flexible  and|CUnochlore(     } 
slightly  elashc.j 
Deep  green.                    p    S.T  93>94-] 

Al2Mg5Si3 
014+4H20. 

Pearly. 

Deep  green. 

Greenish 
\vhite  to 
white. 

| 
fc 

1 

Saline  taste. 

Halite  (17). 

[Compare 

NaCl. 

Vitreous. 

White  to 
gray,  brown, 

White. 

^> 

•^ 

S.T.  56,  57,  68,  69.] 

Opaque.                            'C°m^™  Serpentine. 

CuSiO3 
+2H2O. 

Vitreous 
to  dull. 

Bluish  green 
to  blue. 

Whitish. 

5 

Square    tabular 

Yellow  to 

crystals.     Yellow 

Wulfenite  (41). 

PbMo04. 

Resinous. 

green  and 

White. 

* 

to  orange  and  red. 

brown. 

Green,  rarely           Pyromorphite 

yellow  or  brown.                          (37)- 

3Pb3P208 
+PbCl2. 

Resinous. 

Green  to 
yellow  and 
brown. 

White  or 
yellowish. 

4 

Yellow,  brown 

Mimetite  (37).            -}-PbCl2. 

Resinous. 

Pale  yellow 
to  brown. 

White. 

or  red. 

rt 

Implanted  crystals 

0 

oj  incrustations. 

Vanadinite  (37). 

Compare 

3Pb3V208 
-hPbQ2. 

Resinous. 

Yellow  to 
brown. 

Yellowish 
white. 

Pyrotnorphite. 

White  or  gray 

Anglesite  (42). 

PbS04, 

Adamantine 
to  vitreous. 

White. 

White. 

to  yellowish 

and  brownish. 

Cerussite  (46). 

PbCO3. 

Adamantine 
to  vitreous. 

White  to 
gray. 

White. 

METALLIC     LUSTER. 


67 


H.  |Tenacity 

G. 

Form. 

Cleavage. 

Other 
Properties. 

Confirmatory  Chemical  Tests. 

2-5- 
3- 

Elastic 
and 
sectile. 

2.7- 

3-1 

V.  Tabular 
or  foliated. 

Basal,  very 
perfect. 

Transparent 
to  opaque. 

3.  B.  fuses  with  difficulty;    decom- 
posed by    H2SO4;    reactions   for 
iron;   little  water  in  closed  tube. 

2- 

2-5 

r 

2-5- 

4- 

Elastic 
and 
sectile. 

Elastic 
and 
sectile. 

Elastic 
and 
sectile. 

2-75 
-3- 

2.8 
2.8- 

2.9 

V.  Tabular 
or  foliated. 

V.  Tabular 
or  foliated. 

V.  Tabular 
or  toiiated. 

Basal,  very 
perfect. 

Basal,  very 
perfect. 

Basal,  very 
perlect. 

Transparent 
to 
translucent. 

Transparent 
to 
translucent. 

Translucent. 

3.  B.  infusible;  insoluble;  little 
water  in  closed  tube. 

B.  B.  fuses  with  difficulty;  decom- 
posed by  H2SO4;  Kltle  water  in 
closed  tube. 

B.  B.  fuses  with  intumescence  at  2.5  ; 
coloring  the  flame  purplish  red; 
little  water  in  closed  tube. 

3- 

Sectile  to 
brittle 

3- 
3-2 

V.  Tabular 
or  loliated. 

Basal, 
perfect. 

Translucent 
to  opaque. 

B.  B.  fuses  easily  to  a  black  mag- 
netic globule  ;  decomposed  by 
HC1,  depositing  silica  in  scales. 

3-5- 
4-5 

Laminae 
stiff  and 
brittle 

3- 

V.  Usually 
lamellar  or 
foliated. 

Basal, 
perfect. 

Translucent 

B.  B.  infusible  ;  whitens;  yields  water 
in  closed  tube. 

2- 

2-5 

Flexible 
and 
sectile 

2.7 

V.  Tabular 
or  foliated. 

Basal, 
perfect. 

Transparent 
Emerald- 
green  by 
trans'd  light 

B.  B.  fuses  with  difficulty;  yields 
much  water  in  closed  tube. 

2-5 

Very 
brittle 

2.1- 
2.6 

I.  Cubes,  also 
massive. 

Cubic, 
perfect. 

Transparent 
to 
translucent 
Saline   taste 

B.  B.  fuses  easily,  coloring  flame  deep 
yellow;  soluble  in  water. 

2-4- 

Brittle  to 
sectile 

2- 
2.2 

Compact, 
sometimes 
botryoidal. 

None. 

Opaque. 

B.  B.  infusible;  colors  flame  green; 
yields  water  in  closed  tube;  and 
copper  with  soda  on  charcoal. 

2.75 

-3- 

1 
I  Brittle. 

6.7- 

7- 

11.  Square,  tab- 
ular crystals. 
Often  very  thin. 

Octahedral. 

Translucent 

B.  B.  fuses  readily  (1.5);  yields  me- 
tallic lead  on  charcoal  with  soda. 

3-5- 
4- 

Brittle. 

6.5- 

7-1 

III.  Implanted 
crystals,  and 
often  botryoidal 
or  massive. 

Traces. 

Translucent 

B.  B.  readily  fusible  (1.5);  lead  with 
soda  on  charcoal;  chlorine  with 
CuO  and  SPh  ;  white  sublimate  in 
tube. 

3-5 

2-75 
-3- 

Brittle. 
Brittle. 

7- 
7-25 

6.65 

7-25 

III.  Also 
massive  or 
incrusting. 

III.  Implanted 
crystals,  and 
incrustations. 

Imperfect. 
None. 

Translucent 
Opaque. 

Like  pyromorphite,  but  gives  arsen- 
ical odor  on  charcoal. 

Like  pyromorphite. 

2-75 
-3- 

3- 
3-5 

Brittle. 
Brittle. 

6.1- 
6.4 

6-5 

IV.  Also 
massive  and 
stalactitic. 

IV.  Also 
massive  and 
stalactitic. 

Prismatic, 
interrupted. 
Conchoidal. 

Prismatic, 
imperfect. 
Conchoidal. 

Transparent 
to  opaque 

Transparent 
to  opaque. 

B.  B.  fuses  readily  (1.5);  metallic 
lead  with  soda  on  charcoal;  coin 
test  for  sulphur. 

B.  B.  fuses  readily;  yields  metallic 
lead  with  soda  on  charcoal;  effer- 
vesces with  acid. 

68 


B.     MINERALS     WITHOUT 


Analytical  Key. 

Species. 

Composition 

Luster. 

Color. 

Streak. 

^S 
$ 

•?o 

5 

1 

55i 

1 
& 

<5i 

i 

42 

g 

£x 

1 

| 
£> 
\ 
$t 
% 
^ 

o 

> 

^ 

H 

Effervesces  with 
acid,  evolving 
H2S,  known 
by  odor. 

Sphalerite  (8). 

ZnS. 

Resinous. 

Pale  yellow 
to  brown. 

White  to 

gray. 

PJffervesces  with  acid,  evolving  CO2. 

Rose  -red  to 
brownish 
red. 

Rhodochrosite 

(45). 

MnCO3. 

Vitreous. 

Rose-red 
to  brown- 
ish red. 

White. 

B.  B.  be- 
comes black 
and  mag- 
netic. 

Siderite  (45). 

FeCOa. 

Vitreous. 

Gray  to 
brown. 

White  to 

gray. 

B.  B.  colors 
flame  red, 
color  intense 
with  HCi. 

Strontianite 

(46). 

SrCO3. 

Vitreous. 

White  to 
greenish. 

White. 

B.  B.  colors 
flame  yellow- 
ish green. 

Witherite  (46). 

BaCO3. 

Vitreous. 

White. 

White. 

Not  belong- 
ing to  the 
foregoing 
divisions. 

Smithsonite 

(45)- 

ZnCO3. 

Vitreous 
to  dull. 

Grayish, 
greenish, 
or  brownish 
white. 

White  to 
gray. 

Gelatinizes  with 
H  Cl  in  test 
tube. 

Calamine  (66). 

Zn2SiO4 
+H20. 

Vitreous 
to  dull. 

Gray,  also 
yellow  to 
brown. 

White  to 
gray. 

n 

T3 
** 
$ 

1 

"o 

& 

B.  B.  colors 
flame  red. 

Celestite  (42). 

SrSO4. 

Vitreous. 

White  to 
bluish. 

White. 

B.  B.  colors 
flame 
yellowish 
green. 

Barite  (42). 

[CompareS.  T.  34.] 

BaSO4. 

Vitreous. 

White  to 
bluish  or 
brownish. 

White. 

<N 

U 

> 

ed 

Effervesces  with 

Cold,  dilute 
HCl(l:6X 

Compare  G. 
and  B.  B. 

Calcite  (45). 
Aragonite  (46). 

CaCOg. 
CaCOg. 

Vitreous 
to  dull. 

Vitreous 
to  dull. 

White,  and 
all  colors 
when 
impure. 

White  to 
gray,  etc. 

White  to 
gray. 

White. 

Hot  or 
strong  HCI. 
B.  B.  be- 
comes black 
and  mag- 
netic. 

Siderite  (45). 
Ankerite  (45). 

FeCOg. 

(Ca,Mg,Fe) 
CO3. 

Vitreous. 
Vitreous. 

Gray  to 
brown. 

White,  gray, 
reddish. 

White  to. 
gray. 

White. 

Hot  or 
strong  HCI. 
Crystalline 
or  granular. 

Dolomite  (45). 

(Ca,Mg) 
CO,. 

Vitreous 
to  dull. 

White  to 
gray,  etc. 

White. 

Hot  or 
strong  HCI. 
r*erfectly 
compact. 

Magnesite  (45). 

[Compare  S.  T.  70.] 

MgCOg. 

Vitreous 
to  dull. 

White  to 
gray,  etc. 

White. 

METALLIC     LUSTER. 


69 


H. 

Tenacity 

G. 

Form. 

Cleavage. 

Other 
Properties. 

Confirmatory  Chemical  Tests. 

3-5- 
4- 

Brittle. 

3-9- 
4.1 

I.  Tetrahedral, 
also  massive. 

Dodecahe- 
dral,  perfect. 

Translucent 
to  opaque. 

B.  B.  infusible;  zinc  oxide  coating 
with  soda  on  charcoal;  evolves 
H2S  with  HC1. 

3-5- 
4-5 

Brittle. 

% 

III.  Rhombo- 
heclral,  also 
massive  and 
botryoidal. 

Rhombohe- 
dral,  perfect. 

Translucent. 

B,  B.  infusible;  decrepitates;  ame- 
thystine bead  with  borax;  bluish 
green  with  soda  on  platinum  foil; 
effervesces  with  acid. 

2-4. 

Brittle. 

3-8 

III.  Rhombo- 
hedral,  also 
compact  and 

concretionary. 

Rhombohe- 
dral,  perfect. 

Translucent 
to  opaque. 

B.  B.  nearly  infusible  (4.5);  black- 
ens and  becomes  magnetic;  effer- 
vesces with  acid. 

3-5- 
4- 

^  

3-5 
2-4. 

2-4. 

Brittle. 

3-7 

IV.  Also 
globular, 
massive,  etc. 

Prismatic, 
perfect. 

Transparent 
to  opaque. 

B.  B.  infusible;  intumesces;  colors 
flame  red;  alkaline  reacticfn  after 
ignition;  effervesces  with  HCl,sol. 
gives  white  precip.  with  H2S(J4. 

Brittle. 

4-3 

IV.  Also 
globular, 
botryoidal,  etc. 

Brachypina- 
coid,distinct. 

Translucent 
to  opaque. 

B.  B.  fuses  at  2,  coloring  rlame  yel- 
lowish green  ;  alkaline  reaction  af- 
ter fusion  ;  effervesces  with  HC1, 
sol.  gives  white  precip.  with  H2SC>4. 

Brittle  to 
friable. 

4.2- 
4-5 

3-4- 
3-5 

III.  Rhombohe- 
dral,  usually 
compact  to 
earthy. 

Rhombohe- 
dral,  perfect. 

Translucent 
to  opaque. 

B.  B.  infusible;  effervesces  with 
acid;  zinc  oxide  coating  with  soda 
on  charcoal. 

Brittle  to 
friable. 

IV.  Massive 
to  earthy. 

Prismatic, 
perfect. 

Transparent 
to  opaque. 

B.  B.  infusible  (6)  ;  yields  water; 
blue  color  with  cobalt  solution; 
gelatinizes  with  HC1. 

3- 
3-5 

Brittle. 

4- 

IV.  Also 
massive,  fibrous, 
globular,  etc. 

Basal  and 
prismatic, 
perfect 

Transparent 
to  opaque. 

B.  B.  decrepitates  and  fuses  at  3,  col- 
oring flame  red;  alkaline  reaction 
after  fusion;  sulphur  reaction  with 
Ag  after  fusion  with  soda. 

2-5- 
3-5 

Brittle. 

4-3- 
4.6 

IV.  Also 
massive    and 
stalactitic. 

Basal  and 
prismatic, 
perfect. 

Transparent 
to  opaque. 

B.  B.  decrepitates;  fuses  at  3,  color- 
ing flame  yellowish  green  ;  alkaline 
reaction  after  fusion;  S  reaction 
with  Ag  after  fusion  with  soda  . 

2-3- 

3-4- 

Brittle. 
Brittle. 

2-7 

2.9- 
3- 

III.  Rhombohe- 
drons,  also 
massive, 
compact,  etc. 

IV.  Prismatic, 
also  stalactitic, 
etc. 

Rhombohe- 
dral,  perfect. 

Prismatic, 
imperfect. 

Strong 
double 
refraction. 

Transparent 
to 
translucent. 

B.  B.  infusible;  glows;  alkaline  re- 
action after  heating;  effervesces 
in  cold  dilute  acid. 

Like  calcite,  but  whitens  and  falls  to 
pieces,  B.  B. 

2-4. 

3-5- 
4- 

Brittle. 
Brittle. 

3-8 

2.9- 
3-i 

III.  Also 
compact  and 
concretionary. 

III.  Rhombohe- 
drons,  also 
massive  and 
compact. 

Rhombohe- 
dral,  perfect. 

Rhombohe- 
dral,  perfect. 

Translucent 
to  opaque. 

Translucent 
to  opaque. 

B.  B.  nearly  infusible  (4.5)  ;  black- 
ens and  becomes  magnetic;  effer- 
vesces with  acid. 

B.  B.  infusible;  becomes  black  and 
magnetic  on  charcoal;  alkaline 
reaction  after  ignition. 

3-5- 

4- 

Brittle. 

2.8- 

2.9 

III.  Rhombohe- 
drons,  also 
massive  and 
compact. 

Rhombohe- 
dral,  perfect. 

Translucent 
to  opaque. 

B.  B.  infusible;  alkaline  reaction 
after  heating;  does  not  effervesce 
freely  in  cold,  dilute  acid. 

3-5- 
4-5 

Brittle. 

3- 
3-i 

III.  Usually 
compact. 

Rhombohe- 
dral,  perfect. 

Transparent 
to  opaque. 

Like  dolomite. 

7o 


B.     MINERALS     WITHOUT 


Analytical  Key. 

Species. 

Composition 

Luster. 

Color.                Streak. 

Gelatinizes  with 
HC1  in  test  tube. 

Calamine  (66). 

Zn2SiO4 

-MI20. 

Vitreous 
to  dull. 

Gray,  also 
yellow  to 
brown. 

White  to 
gray. 

^  <u   Decrepitates 
g"d   whenheat'd 
o        Phosphores- 

Fluorite (18). 

CaF2. 

Vitreous. 

White, 
green,  violet 
to  blue, 

White. 

<u 
fl 

ce                       cent. 

yellow,  etc. 

^ 

.0 

«       Alkaline 
reaction 
"0       after  heat- 

Cryolite (18). 

Na3AlF6. 

Vitreous. 

White  to 
brown. 

White. 

>n 

ing. 

O 

o       Compare  H. 
j^          and  fusi- 
S                     bility. 

Anhydrite  (42). 

CaSO4. 

Vitreous 
to  pearly 

White  to 
bluish  or 
reddish. 

White. 

0 

Much  water  in 
closed  tube. 

Serpentine  (78). 

Mg3SioO7 
+  2H2O. 

Resinous, 
waxy, 
greasy 

Green, 
yellow, 
brown,  etc. 

White. 

Compare  fusi- 

*£ 

bility. 

Finite  (75). 
^Compare  S.  T. 

K2A1  Si  O 
+3H20. 

Waxy 
to  dull. 

Gray  to 
green. 

White. 

- 

47,52,65.] 

5 

White  to 

1 

1 

S 

Acicular  or 

Wavellite  (39). 

+I2H2O. 

Vitreous. 

green, 
brown,  etc. 

White. 

•2 

(ibrous. 

2 

S 

1 

Compare  form. 

Serpentine 

(Chrysotile)  (78). 

Mg8Si207 
+2H2O. 

Silky. 

Green  to 
yellowish 

White. 

« 

Compare  Asbestus. 

green. 

6 

GQ 

Brucite  (31). 

MgO 
+H2O. 

Pearly. 

White  to 
greenish. 

White. 

e 

Only  one  perfect 

^ 

cleavage. 
Pearly  luster  on 
cleavage  faces. 
Compare  H.  and 

Stilbite  (70). 

(CaNa2Al)2 
+6H  O. 

Pearly. 

White  to 
yellow  and 
red. 

White. 

fusibility. 

(CaNa2Al)2 

White  to 

Heulandite  (69). 

Si6O16 

Pearly. 

red,  gray, 

White. 

0 

i 

Compare  Gypsum. 

+5H20. 

and  brown. 

d 

Compact. 
Floats  on  water 
when  dry. 

Sepiolite  (78). 

Mg2Si308 
+2H20. 

Dull. 

White. 

White. 

Compact  or 
incrusting. 

Gibbsite  (31). 

A12O3 

Vitreous 
to  pearly 

White  to 

White. 

Argillaceous  odor. 

Compare  S.  T.  96.] 

-hoH20. 

and  dull. 

gray. 

Perfectly 
compact  or 
amorphous. 

Deweylite  (78). 
Compare  Serpentine. 

Mg4Si3O9 
+oH2O. 

Greasy. 

Yellow  to 
gray  and 
greenish. 

White. 

C      t  llii 

Water  in  closed 

tube. 

Laumontite 

(7°)- 

CaAloSi4O12 
+4H20. 

Vitreous. 

White  to 
red. 

White. 

Compare  S.T.  63.] 

METALLIC     LUSTKR. 


H. 

Tenacity 

G. 

Form. 

Cleavage. 

Other 

Confirmatory  Chemical  Tests. 

2-4. 

Brittle  to 
friable. 

3-4- 
3-5 

IV.  Massive 
or  earthy. 

Prismatic, 
perfect. 

Transparent 
to  opaque. 

B.  B.  infusible  (6);     yiems  water; 
blue   color  with  cobalt  solution; 
gelatinizes  with  HC1. 

4- 

Brittle. 

3- 
3-25 

I.  Cubes,  also 
massive. 

Octahedral, 
perfect. 

Phosphores- 
cent, when 
heated. 

B.  B.  decrepitates,   fuses  at  3,  and 
gives  alkaline  reaction;    reaction 
for  fluorine  with  HKSO*. 

B.  B.  fuses  very  easily  (i),  coloring 

2-5 

Brittle. 

3- 

V.  Usually 
massive. 

Imperfect. 

Translucent. 

flame  yellow;    fluorine    reaction 
with  potassium   bisulp'liate  (HK 

S04). 

3- 

3-5 

Brittle. 

2-9- 
3- 

IV.  Often 
compact. 

None 
•apparent. 

Translucent 
to  opaque. 

B.  B.  fusible  at  3;  alkaline  reaction; 
sulphur  reaction    on   silver   after 
fusion  with  soda. 

2-5- 
4- 

Brittle. 

2-5- 
2.05 

Compact  or 
foliated. 

None. 

to  opaque. 
Smooth  feel. 

B.  B.  infusible;  yields  water  in  closed 
tube;   decomposed  by  HC1. 

2-5- 
3-5 

Brittle. 

2.6- 

2.8 

Compact. 

None. 

Translucent 
to  opaque. 

B.  B.  fusible  ;   yields  water  in  closed 
tube. 

3-25 
-4- 

Brittle. 

2.3 

IV.  Usually 
in  radiate, 
globular 

Prismatic, 
perfect, 

Translucent. 

B.  B.  swells  up,  colors  flame  green, 
but  is  infusible;    blue  color  with 
cobalt  solution;    much  water   in 

masses. 

tube. 

2-5- 
4- 

Flexible 
and 
sectile 

2.2- 
2.0 

Fibrous  veins. 

Delicately 

fibrous. 

Translucent. 

B.  B.  infusible  ;  yields  water  in  closed 
tube;  decomposed  by  HCl. 

2-5 

Flexible 
and 

2.4 

III.  Usually 
foliated. 

Basal, 
perfect. 

Translucent. 

B.  B.  infusible;     alkaline    reaction 
after  heating;    red  color  with  co- 
balt solution;     water    in    closed 

sectile 

tube;  soluble  in  acid. 

3-5- 

4- 

Brittle. 

2- 
2.2 

V.  Usually  in 
sheaf-like 
aggregates. 

Clinopina- 
coidal, 
perfect. 

Transparent 
to 
translucent. 

B.  B.  fuses  at     2.5  with     intumes- 
cence;    yields    water    in   closed 
tube;   decomposed  by  HCl,  with- 
out gelatinizing. 

V.  Also 

Clinopina- 

Transparent 

3-y- 

4- 

Brittle. 

2.2 

globular  and 
massive. 

coidal, 
perfect. 

to 
translucent. 

Like  stilbite. 

Some- 

Very 

Opaque. 

B.  B.  infusible;  water  in  closed  lube; 

2- 

what 

light 

Compact. 

None. 

Absorbs 

pink  color  with  cobalt  solution; 

2-3 

sectile 

-2. 

water. 

gelatinizes  with  HCl. 

2-5- 
3-5 

Tough. 

2-3- 
2.4 

V.  Usually 
stalactitic  or 
incrusting. 

Basal, 
perfect. 

Translucent. 
Argillaceous 
odor. 

B.  B.  infusible;    yields  water;    blue 
color  with  cobalt  solution. 

2- 

3-5 

Brittle. 

2- 
2.2 

Compact. 

None. 

Translucent. 

B.  B.  infusible;  yields  water  in  closed 
tube;  decomposed  by  HCl. 

2.25 

V.  Also 

Becomes 

B.  B.   fuses    easilv,  with    intumes- 

3-5- 

4- 

Brittle. 

to 
2-35 

columnar  and 
massive. 

Perfect. 

opaque  and 
pulverulent 

cence;      yields   water   in     closed 
tube;    gelatinizes  with  HCl. 

B.     MINERALS    WITHOUT 


Analytical  Key. 

Species. 

Composition 

Luster. 

Color. 

Streak. 

V 
"rt    rt° 
S    > 

3ark  gray, 
green  or 
black. 

Chloritoid  (76). 

(Fe,Mg)Al2 
SiO6+H2O. 

'early. 

3ark  gray 
and  green- 
sh  to  black. 

jrayish  to 
greenish. 

M              | 

led  or  pink 

Margarite  (76). 

CaAl4Si2On 
+H20. 

3early. 

Pink  to 
reddish 
white  or 
crrav 

White. 

I              ^ 

:o  yellowish 

Reddish 

b 

or  gray. 

Seybertite  (76). 

(Mg,Ca)5 
Al6Si2Oi8 
+H20. 

Pearly  sub- 
metallic. 

brown, 
yellowish, 
copper-red. 

White  or 
gray. 

U 

quietly. 

Pectolite  (50). 

Na2Ca4Si2 
Oi7-r-H20. 

Silky  to 
vitreous. 

White. 

White. 

Compare  G. 

o| 

t/3 
3    V 

and  fusion 
products. 

Natrolite  (73). 

Na2Al2Si3 

Vitreous. 

White. 

White. 

o  .S 

1U                         £t 

£  c 

^ 

|3 

Fuses  with 
ntumes- 
cence. 

Thomsonite 

(74)- 
Compare 

(Ca,Na2) 
Al2Si2O8 

Vitreous  to 
pearly 

White. 

White. 

S 

S.T.  91,92.] 

1 

%  ^  E 

o  '5  ^ 

Wrater  in 
closed  tube. 

Serpentine 

(Chrysotile)  (78). 

Mg3Si2O7 
+2H2O. 

Silky. 

Green  to 
yellowish 

White. 

Sto 

:§  5  '^ 

Compare  Asbestus. 

5 

<u   ^ 

5^ 

•g 
3 

r=U      _ 

No  water  in 
closed  tube. 

Amphibole 

(Asbestus)  (51). 

(CaMgFe) 
SiO3 

Vitreous  to 
silky 

White  to 
green 

White. 

W 

Q 

[Compare  S.  T.  79.] 

g 

•8 

T3     • 

Fuses 
quietly 

Pectolite  (50). 

Na2Ca4Si6 
Oi7+H20 

Silky  to 
vitreous 

White. 

White. 

V 

"rt  "§ 

Compare  G. 

gg 

~  ^ 

and  fusion 

• 

1: 

11 

products 

Natrolite  (73). 

Na2Al2Si3 
010-f2H20 

Vitreous. 

White. 

White. 

I'2 
O   j_* 
CJ    cs 

Fuses  with 
intumes- 
cence. Gelat 

Thomsonite 

(74) 
Compare  Allanite. 

(Ca,Na2) 
Al2Si208 

Vitreous  to 
pearly 

White. 

White. 

.H  g- 

with  HC1 

\  Compare  also 
S.T.  91,92.] 

+5H20 

1^ 

Fuses  with 
iutumes- 
cence.   Does 
not  gelat 

Stilbite  (70). 

Compare    Wavelh'te 

(CaNa2)Al2 
Si6016 
+6H2O 

Pearly. 

White 
to  yellow 
and  red 

White. 

^1 

Gelatinizes 
with  HC1 

Wollastonite 

(47) 

CaSiO8. 

Vitreous. 

White  to 
reddish 

White. 

|| 

Compare  Allanite. 

il 

§5 

Do  not 
gelatinize 

Amphibole 
(Tremolite,  Actin- 
olite,  Horn- 
blende) (51) 

(CaMgFe 
Al)SiO3 

Vitreous  to 
silky 

White  to 
green  and 
black 

White. 

ij 

with  HC1 

Cyanite  (60). 

Compare  Epidote. 
[Compare  also 

Al2SiO5. 

Vitreous  to 
pearly 

Blue  to 
white,  green 
and  gray 

White. 

S.  T.  79.] 

METALLIC     LUSTER. 


73 


H. 

Tenacity 

G. 

Form. 

Cleavage. 

Other 
Properties. 

Confirmatory  Chemical  Tests. 

6.5 

Brittle. 

3-5 

V.  or  VI. 

Coarsely 
foliated 
or  scaly. 

Basal, 
perfect. 

Translucent 
to  opaque. 

B.  B.  infusible;   becomes  magnetic; 
yields  water  in  closed  tube. 

3-5- 
4-5 

Laminae 
stiff  and 
brittle. 

3- 

V.  Usually 
lamellar  or 
foliated. 

Basal, 
perfect. 

Translucent. 

B.  B.  infusible;  whitens;  water  in 
closed  tube. 

4-5- 
5- 

Brittle. 

3- 
3-i 

2.7 

V.  Usually 
lamellar 
or  foliated. 

Basal, 
perfect. 

Translucent. 

B.  B.  infusible;  whitens;  water  in 
closed  tube. 

Brittle. 

V.  Acicular 
or  fibrous 
and  radiate. 

Orthopina- 
coidal  and 
basal, 
perfect. 

Translucent 
to  opaque. 

B.  B.  fuses  (2.5)  to  a  white  enamel; 
yields  water  in  closed  tube;  gelat- 
inizes with  HC1. 

5- 

5-5 

Brittle. 

2.2 

IV.  Acicular 
or  fibrous 
and  radiate. 

Prismatic, 
perfect. 

Transparent 
to 
translucent. 

B.  B.  fuses  quietly  at  2  to  a  colorless 
glass;  yields  water  in  closed  tube; 
gelatinizes  with  HC1. 

5- 
5-5 

2-5- 
4- 

Brittle. 

2-3- 

2.4 

IV.  Acicular 
and  radiate, 
also  massive. 

Pinacoidal, 
perfect. 

Translucent. 
Pyroelectric. 

B.  B.  fuses  with  intumescence  at  2; 
yields  water  in  closed  tube;  gel- 
atinizes with  HC1. 

Flexible 
and 
sectile 

2.2- 
2.6 

Fibrous  veins. 

Delicately 
fibrous. 

Translucent. 

B.  B.  infusible;  water  in  closed 
tube;  decomposed  by  HC1. 

5-6. 
5- 

Brittle  tc 
flexible 

2.9- 
3-2 

V.  Usually 
bladed,  fibrous, 
or  asbestiform. 

Prismatic, 
perfect. 

Translucent. 

B.  B.  fusible  2.5-5;    insoluble. 

Brittle. 

2-7 

V.  Acicular 
or  ribrous 
and  radiate. 

Orthopina- 
coidal  and 
basal, 
perfect. 

Translucent 
to  opaque. 

B.  B.  fuses  (2)  to  a  white  enamel; 
yields  water  in  closed  tube;  gelat- 
inizes with  HC1. 

5- 
5-5 

Brittle. 

2.2 

IV.  Acicular 
or  fibrous 
and  radiate. 

Prismatic, 
perfect. 

Transparent 
to 
translucent. 

B.  B.  fuses  quietly  (2)  to  a  colorless 
glass;  yields  water  in  closed  tube; 
gelatinizes  with  HC1. 

5- 
5-5 

Brittle. 

2-3- 
2.4 

IV.  Acicular 
and  radiate, 
also  massive. 

Macropina- 
coidal, 
distinct. 

Translucent. 
Pyroelectric. 

B.  B.  fuses  with  intumescence  at  2; 
yields  water  in  closed  tube;  gelat- 
inizes with  HC1. 

3-5- 
4- 

Brittle. 

2- 

2.2 

V.  Usually  in 
sheaf-like 
aggregates. 

Clinopina- 
coidal, 
perfect. 

Transparent 
to 
translucent. 

B.  B.  fuses  at  2.5  with  intumescence; 
yields  water  in  closed  tube;  de- 
composed by  HC1  without  gelat- 
inizing. 

4-5- 
5« 

5-6. 

Tough. 

2.8- 
2.9 

V.  Tabular 
or  bladed 
to  fibrous. 

Macropina- 
coidal  and 
basal, 
distinct. 

Translucent 
to 
transparent. 

B.  B.  fusible  (4.5)  ;  gelatinizes  with 
HC1. 

Brittle. 

2.9 
32 

V.  Usually 
bladed,  fibrous, 
or  asbestiform. 

Prismatic, 
perfect. 
Angles 
124°  II  . 

Translucent 
to  opaque. 

B.  B.  fusible  (2.5-5);   insoluble. 

5- 
7-25 

Brittle. 

3-6 

VI.  Coarsely 
bladed. 

Pinacoidal, 
distinct. 

Translucent. 

B.  B.  infusible;  insoluble;  blue  color 
with  cobalt  solution  after  ignition. 

74 


1).     MINERALS     WITHOUT 


Analytical     Key.                         Species. 

Composition 

Luster. 

Color. 

Streak. 

V.  Streak  White  or  Gray.  —  Continued. 

3.  Hard.  —  Continued. 

00 
r*> 

U 

j 
(« 

00 

oi 

I 

5 

w 

Powder  effervesces  with  HC'l, 

Evolving 
C02.      B.  B. 
Becomes 
magnetic. 

(Siderite  45). 

FeC03. 

Vitreous 
to  dull. 

Light  to  dark 
gray,  dull 
yellow  and 
brown. 

White  to 
gray. 

Evolving 
CO2. 
Reactions 
fur  zinc. 

Smithsonite 

(45)- 

ZnCO3. 

Vitreous 

to  dull. 

Gray,  green, 
blue  or 
brown  to 
white. 

White  to 
gray. 

Evolving 
H2S. 
Reactions 
for  zinc. 

Sphalerite  (8). 

[Compare  S.  T.  72.] 

ZnS. 

Resinous. 

Pale  yellow 
to  brown. 

White  to 
gray. 

Powder  gelatinizes  with  H  Cl. 

Dark  brown 
to  black. 

Allanite  (62). 

Complex 
silicate. 

Submetallic 
to  resinous. 

Pitch-brown 
to  black. 

Gray. 

Not  dark 
colored 
Compare 
colors. 

Tephroite  (56). 
Willemite  (57). 

Compare  Calamine. 

Mn2SiO4. 
Zn2SiO4. 

Vitreous 
to  greasy. 

Vitreo- 
resinous, 
weak. 

Red  or 
brown  to 
gray. 

Yellowish, 
greenish, 
brownish. 

Pale  gr^y. 

White  and 
reddish. 

JA 

1 

£ 

T3 
<U 

1 

1 

Submetallic. 
Black. 
Massive. 

Chromite  (23). 

FeCr2O4. 

Submetallic. 

Iron-black. 

Brownish 
gray, 

Submetallic. 
Brown  to 
black,  etc. 
Crystals. 

Brookite  (27). 

TiO2. 

Adamantine 
to 
submetallic. 

Brown  to 
yellowish, 
reddish  and 
black. 

White  to 
gray. 

White  or 
nearly  so. 

Scheelite  (41). 

CaWO4. 

Vitreous. 

White  to 
pale  yellow 
and  reddish. 

White. 

Green  to 
brown. 
H.  about  4. 

Pyromorphite 

(37). 

3Pb3P208 
+PbCl2. 

Resinous. 

Green  to 
yellow  and 
brown. 

White  or 
yellowish. 

Red  to 
brown. 
H.  above  5. 

Monazite  (36). 
Compare  S.  T.  35.] 

(Ce,La,Di) 
P04. 

Inclining  to 
resinous. 

Red  to 
brown. 

Gray  to 
white. 

go 
3  a 

_        Ctf 

«    & 

*J 

Yields  water 
in  closed 
tube. 

Lazulite  (39). 

MgAl2P2O9 
+H20. 

Vitreous. 

Blue. 

White. 

Yields  little 
or  no  water. 

Lazurite  (54). 

Na4(NaS3 
Al)Al2Si8 
Oi2. 

Vitreous. 

Blue. 

Blue  to 
gray. 

£ 

-6  £ 

1>     03 

^X       c-\ 

^  a 

a 

Powder 
effervesces 
with  HCI. 

Rhodochrosite 

(45)- 

MnCO3. 

Vitreous. 

Rose-red 
to  brown. 

White. 

Does  not 
effervesce. 

Rhodonite  (50). 

MnSiO3. 

Vitreous. 

Red  and 
brown  to 
gray. 

White. 

METALLIC     LUSTER. 


75 


H. 

Tenacity 

G. 

Form. 

Cleavage. 

Other 
Properties. 

Confirmatory  Chemical  Tests. 

2-4. 

Brittle. 

3-8 

III.  Also 
compact  and 
concretionary. 

Rhombo- 
hedral, 
perfect. 

Translucent 
to  opaque. 

B.  B.  nearly  infusible  (4.5)  ;  black- 
ens and  becomes  magnetic;  effer- 
vesces with  acid. 

2-4. 

Brittle 
to 
friable. 

4.2- 
4-5 

III.  Usually 
compact  to 
earthy. 

Rhombo- 
hedral, 
perfect. 

Translucent 
to  opaque. 

B.  B.  infusible;  effervesces  with 
acid;  zinc  oxide  coating  with  soda 
on  charcoal. 

3-5- 
4- 

Brittle. 

3-9- 
4.1 

I.  Also 
massive. 

Dodecahe- 
clral,  perfect. 

Translucent 
to  opaque. 

B.  B.  infusible;  zinc  oxide  coating 
with  soda  on  charcoal;  reactions 
for  sulphur;  evolves  H^S  with 
HC1. 

5-5- 
6. 

Brittle. 

3-5- 
4.2 

V.  Also 
massive  and 
granular. 

In  traces. 

Opaque. 

B.  B.  fuses  with  intumescence  to  a 
magnetic  mass. 

5-5 

Brittle. 
Brittle. 

4- 
4.1 

3-9- 
4.2 

IV.  Usually 
massive. 

III.  Usually 

massive,  also 
hexagonal 
crystals. 

Distinct. 
Imperfect. 

Translucent. 

Translucent 
to  opaque. 

B.  B.  fuses  at  3.5  to  a  black  scoria  ; 
gelatinizes  with  HC1. 

B.  B.  fuses  with  difficulty  (3.5-4)  ; 
coating  of  zinc  oxide  with  soda 
on  charcoal;  gelatinizes  with  HCl. 

5-5 

Brittle. 

4-3- 
4.6 

I.  Usually 
massive. 

None. 

Opaque. 
Sometimes 
magnetic. 

B.  B.  infusible;  becomes  magnetic; 
green  bead  with  borax. 

l:s' 

Brittle. 

3-9- 
4- 

IV.  Rarely 
massive. 

Imperfect. 

Translucent. 

B.  B.  infusible;  insoluble. 

4-5- 

5- 

Brittle. 

5-9- 
6.1 

II.  Habit 
octahedral, 
also  massive. 

Indistinct. 

Transparent 
to 
translucent. 

B.  B.  fuses  with  difficulty  (5)  to  a 
glass;  decomposed  by  acid. 

3-5- 
4- 

I  kittle. 

6.5- 
7-1 

III.  Often 
botryoidal 
or  massive. 

Traces. 

Translucent. 

B.  B.  readily  fusible  (1.5)  ;  lead  with 
soda  on  charcoal;  chlorine  with 
CuOand  SPh;  white  sublimate  in 
closed  tube. 

5- 
5-5 

Brittle. 

4.9- 
5-3 

V.  Also 
massive  and 
in  grains. 

Distinct. 

Translucent. 

B.  B.  infusible,  turns  gray,  and  gives 
bluish  green  flame  after  moisten- 
ing with  H2SO4- 

5-6. 

3rfttle. 

3- 
3-i 

V.  Octahedral, 
also  massive. 

Imperfect. 

Opaque. 

B.  B.  infusible;  falls  to  pieces  and 
whitens;  blue  color  is  restored  by 
cobalt  solution;  yields  water  in 
closed  tube. 

5- 

5-5 

Brittle. 

2.4 

1.  Usually 
compact. 

None. 

Opaque. 

B.  B.  fuses  (3)  to  a  white  glass;  gel- 
atinizes with  HCl. 

3-5- 
4-5 

Brittle. 

jr 

III.  Also 
massive  and 
botryoidal. 

Rhombo- 
hedral, 
perfect. 

Translucent. 

B.  B.  infusible;  decrepitates;  ame- 
thystine bead  \\ith  borax;  bluish 
green  with  soda  on  platinum  foil; 
effervesces  with  acid. 

*r 

Tough. 

3-4- 
3-7 

VI.  Usually 
compact  or 
massive. 

Indistinct. 

Translucent 
to  opaque. 
Blackens 
on  exposure. 

B.  B.  blackens  and  fuses  at  2.5  ;  am- 
ethystine bead  with  borax. 

B.     MINERALS  WITHOUT 


Analytical    Key. 

Species. 

Composition 

Luster. 

Color. 

Streak. 

Powder  effer- 

Dolomite (4$). 

(CaMg) 
C03 

Vitreous 
to  dull 

White  to 
gray,  etc. 

White. 

vesces  with  HC1. 

Compare  form. 

Magnesite  (45) 

Compare  Siderite,  • 
Smithsonite  and 

MgC03. 

Vitreous 
to  dull. 

White  to 
gray,  etc 

White. 

A  nkerite 

0 

Much  water 
in  closed 

Datolite  (61). 

'   20i20 

Vitreous. 

White  to 
gray,  red, 
etc 

White. 

K 

tube. 

,£! 

Compare  G., 

izes  wit 

form,  and 
fusibility. 

Calamine   (66). 
Compare  Pectolite. 

Zn2SiO4 
+H,0. 

Vitreous. 

White. 

White. 

t 

Little  or  no 

Wollastonite 

(r0). 

CaSi03. 

Vitreous. 

White  to 
reddish. 

White. 

•  , 

water  in 

<u 

closed  tube. 

1 

I 

Compare 
form. 

Chondrodite 

(65). 

H2Mg19Si8 
034F4. 

Vitreous  to 
resinous. 

Yellow 
and  brown 

White  to 
gray. 

5 

Compare  Allamte. 

g 

-A 

White, 

0 

1 

I 

Alkaline  reac- 

Fluorite  (18). 

CaF2. 

Vitreous. 

yreen  ,  violet, 

White. 

1 

a 

tion  after 

to  blue, 

i> 

_s 

s 

heating. 

yellow,  etc. 

t. 

o 

a 

? 

00 

Compare  form 
and  cleavage. 

Apatite  (37). 

3Ca3P208 
+CaCl2. 

Vitreous. 

Green  to 
brown, 
yellow, 

White. 

<c 

^s 

CJ 

white,  etc. 

•~ 

I 

Squarish, 

Brown, 

* 

en 

1 

e) 

wedge-shaped 
or  oblique 

Titanite  (81). 

CaTiSiO5. 

Adamantine 
to  resinous. 

yellow, 
green, 

White  to 
gray. 

1 

O 

crystals.'' 

black. 

* 

Compact. 

Epidote  (62). 

H2Ca4FeAl2 
Si6O26. 

Vitreous. 

Yellowish 
green. 

Gray. 

Gre 

en. 

Compare  color. 

Jadeite  (50). 

NaAlSi2O6. 

Subvitreous. 

Green  to 

White.     ' 

[CompareS.  T.  38.] 

Fusible. 

Pyroxene  (50). 

(CaMgAl 
Fe)SiOg. 

Vitreous. 

Green  to 
jray,  brown, 
Dlack,  white. 

White  to 
greenish 
gray. 

Cor 

upare  U. 

and  cleavage. 

Amphibole  (51). 

Compare  IVernerite- 
[Compare,  also, 

(CaMgAl 

Fe)SiO3. 

Vitreous. 

Green  to 
white,  gray, 
brown, 

White  to 
greenish 

S.  T.  39.  41,  42.] 

black. 

gray. 

Vitreous  to 

Gravish  and 

Infusible  or 

Enstatite  (50). 

MgSi08. 

pearly  and 
metalloidal. 

greenish  to 
brown. 

White  to 
gray. 

fuse  with 

difficulty. 

Hypersthene 
(50). 

[Compare 

(MgFe) 
SiO3. 

Pearly  to 
metalloidal. 

Dark  brown- 
ish green 
to  brown 

Gray. 

S.T.  40,74,  79.] 

and  black. 

METALLIC  LUSTER. 


r, 


H. 

Tenacity     G. 

Form. 

Cleavage. 

O  her 
Properties. 

Confirmatory  Chemical  Tests. 

3-5- 
4- 

Brittle. 

2.8- 

2.9 

III.  Rhombo- 
hedrons,  also 
massive  and 

Rhombohe- 
dral,  perfect. 

Translucent 
to  opaque 

B.  B.  infusible;  alkaline  reaction  af- 
ter heating  ,  does  not  effervesce 
freely  in  cold,  dilute  acid. 

compact. 

3-5- 

4-5 

Brittle. 

3- 
3-1 

III.  Usually 
compact. 

Rhombohe- 
dral,  perfect. 

Transparent 
to  opaque 

Like  dolomite 

V    Ako 

B.  B.  fuses  (2)  with  intumescence; 

5- 
5-5 

Brittle. 

2.9- 

3- 

globular  and 
compact. 

None. 

Translucent 
to  opaque 

and  colors  flame  bright  green; 
much  water  in  closed  tube;  gelat- 
inizes with  HC1. 

4-5- 
5- 

Brittle. 

3-4- 
3-5 

IV.  Also 
botryoidal 
and  massive 

Prismatic, 
,  perfect 

Translucent. 

B.  B.  infusible  (6);  yields  water  in 
closed  tube;  green  color  with 
cobalt  solution;  gelatinizes  with 
HC1. 

V.  Tabular  and 

4-5- 
S- 

Tough. 

2.8- 

2.9 

bladed  to 
fibrous  and 

None. 

Translucent. 

B.  B.  fuses  (4.5)  ;  gelatinizes  with 
HC1. 

compact 

6- 
6.5 

Brittle. 

3-2 

V.  Usually 
in  rounded 
grains. 

None. 

Translucent 
to  opaque 

B.  B.  infusible;  gelatinizes  with  HC1. 

4- 

Brittle. 

3- 
3-25 

I.  Cubes, 
octahedrons, 
also  massive 

Octahedral, 
perfect 

Phosphores- 
cent when 
gently 
heated 

B.  B.  decrepitates,  fuses  at  3,  and 
gives  alkaline  reaction;  reaction 
for  fluorine  with  K2SO4. 

5- 

Very 

brittle. 

3-2 

III.  Prisms  and 
massive  or 
granular. 

Basal, 
imperfect 

Transparent 
to  opaque 

B.  B.  fuses  with  difficulty  (4.5-^,); 
reaction  for  phosphorus  with  mag- 
nesium; soluble  in  acid. 

5- 
5-5 

Brittle. 

3-4- 
3-55 

V.  Crystals, 
and  cleavable 
massive. 

Prismatic, 
perfect. 

Translucent 
to  opaque. 

B.  B.  fuses  with  intumescence  (3) 
to  a  dark  glass. 

6-7. 

Brittle. 

3-25 
to 

3-5 

V.  Compact 
to  finely 
granular. 

None. 

Opaque. 

B.  B.  fuses  (3-3.5)  with  intumes- 
cence to  a  magnetic  mass;  yields 
water  in  closed  tube  when  strong- 
ly heated. 

6.5- 
7- 

Very 
tough. 

3-3 

Massive  or 
compact. 

S.plintery. 

Translucent. 

!3.  B.  fuses  readily  to  a  transparent 
blebby  glass;  unaffected  by  acids. 

5-6. 

Brittle. 

3- 

3-5 

V.  Often 
massive  and 
granular. 

Prismatic, 
distinct. 
Yngle= 
87°5'. 

Transparent 
to  opaque. 

B.  B.  fusible  (2.5-5)  '>  insoluble. 

Prismatic, 

5-6. 

Brittle. 

2.9- 

V.  Often  bladed 
or  massive. 

perfect. 
\ngle  — 

Transparent 
to  opaque. 

3.  B.  fusible  2.5-5;   insoluble. 

5-5 

Brittle. 

3-3 

V.  Also  massive, 
fibrous  and 
lamellar 

.Msmatic, 
distinct. 
Angle=: 

Translucent 
to  opaque. 

3.  B.  almost  infusible  (6)  ;  insoluble. 

91  44- 

5-6. 

Brittle. 

3-4- 

3-5 

IV.  Also 
massive,  tabular 
and  lamellar. 

Prismatic, 
distinct. 
\ngle= 

Translucent 
to  opaque. 

B.  B.  fusible  with  difficulty  to  a  black, 
magnetic  mass  on  charcoal. 

9i°4o'. 

78 


B.     MINERALS     WITHOUT 


Analytical  Key. 

Species. 

Composition 

Luster. 

Color.                Streak. 

Turquois  (39). 

A14P20U 
+5H20 

Waxy 
to  dull 

Sky-blue  to 
greenish 

hlnp 

White  to 
greenish 

Deep  blue. 

Compare  G. 

Sodalite  (54). 

3NaAlSi04 
+NaCl 

Vitreous 
to  greasy 

Gray,  blue, 
green,  white, 
yellow,  etc. 

White. 

Compact. 
Waxv  luster 
Usually 
green 

Serpentine  (78) 

Mg3Si2O7 

Resinous, 
waxy, 
greasy 

Green, 
yellow, 
brown,  etc. 

White. 

Amorphous. 
Opaline. 

Opal  (34). 

SiO2-fM2O. 

Vitreous 
to  resinous 
or  pearly 

Various 

colors. 

White. 

Powder 
gelatinizes 
with  HC1. 

Laumontite 

(70). 
Compare  Apophylhte 
and  Analcite. 

CaAl2Si4O12 
+4H20 

Vitreous. 

White  to 
red. 

White. 

1 

•e 

Do  not 

Apophyllite 

(68). 

4(H2CaSi2 
06)-f-KF 

Vitreous 
to  pearly 

White  to 
yellowish 
or  greenish. 

White. 

» 

i 

gelatinize 

3 

1 

g; 

u 
B 

with  HC1 
Fuse  quietly 
Compare 

Analcite  (72). 

STa2Al2Si4 
O12+2H2O 

Vitreous. 

White. 

White. 

e* 

is 

00 

I 

crystalline 

! 

ss 

a 
4 

~ 

£ 

form. 

Gmelinite  (71). 

Na2Al2Si4 
012-|-t)H2O 

Vitreous. 

White  to 
greenish, 
reddish,,  etc. 

White. 

*s 

a 

o 

i 

* 

Do  not 
gelatinize 

Chabazite  (71). 

K2CaAl2Si5 
015+6H2O 

Vitreous. 

White  to 
red. 

White. 

53 

with  HC1. 

is 

Fuse  with 

; 

intumes- 
cence. 

Heulandite(69). 

H4CaAl2Si6 
Oi8-f-3H20. 

Vitreous 
t<>  pearly 

red,  gray, 

etr 

White. 

*• 

Compare 

'  crystalline 
form  and 
cleavage. 

Stilbite  (70). 

Compare 

(CaNa2)Al2 
Si6()16 
-r-6H2O. 

Pearly. 

\Vhite  to 
yellow  and 
red. 

White. 

S.  T.  53,90-1 

i 

Powder 
gelatinizes 
with  HC1. 

Nephelite  (53). 

Compare  Sodalite, 

S:a2Al2Si2 
08. 

Vitreous 
to  greasy. 

\Vhite  to 
gray  or 
yellow. 

White. 

V 

I 

Leucite  (49). 

KAlSi2O6. 

Vitreous. 

White. 

0 

Do  not 

gray. 

3 

gelatinize 

h 

with  HC1 

rt 

Compare 
crystalline 

Wernerite  (58). 

JaAl2Si208. 

Vitreous. 

White,  gray, 
reddish,  etc. 

White. 

o 
B 

form  and 

(A 

^£ 

cleavage. 

Labradorite 

(48). 
Compare  S.  T.  31, 

NaCa)Al2 
Si  010. 

Vitreous 
to  pearly. 

Gray  to 
greenish 
and  reddish. 

\Vhite. 

74,  78,  84.] 

METALLIC     LUSTER. 


79 


H. 

Tenacity 

G. 

Form. 

Cleavage. 

Other 
Properties. 

Confirmatory  Chemical  Tests. 

6. 

Brittle. 

2.6- 
2.8 

\morphous, 
incrusting, 
seams  and 

^one. 

Opaque. 

B.  B.  infusible  ;  yields  water  in  closed 
tube  and  turns  brown;  soluble  in 
HC1. 

grams. 

5-5- 

Brittle. 

2.3 

'..  Dodecahe- 
drons, and 
massive. 

Dodecahe- 
dral,  distinct. 

Translucent 
to 
transparent. 

B.  B.  fuses  (3.5—4)  with  intumes- 
cence; gelatinizes  with  HC1. 

2-5- 
4- 

Brittle. 

2-5- 

2.65 

Compact  or 
foliated  . 

Mone. 

Translucent 
to  opaque. 
Smooth  feel. 

B.  B.  infusible  ;  yields  water  in  closet  '. 
tube  ;  decomposed  by  HC1. 

Amorphous. 

Transparent 

5-5- 
6-5 

Brittle. 

1.9- 
2.3 

Sometimes 
botryoidal  or 

None. 

to 
translucent. 

B.  B.  infusible  ;  water  in  closed  tube. 

stalactitic. 

3-5- 
4- 

Brittle. 

2.25 

2-35 

V.  Also 
columnar  and 
massive. 

Perfect. 

Becomes 
opaque  and 
pulverulent 

B.  B.  fuses  easily  with  intumescence; 
yields  water  inclosed  tube;  gel- 
atinizes with  HC1. 

on  exposure. 

4-5- 
5- 

Brittle. 

2-3- 

2.4 

II.  Square 
crystals,  also 
massive. 

Basal, 
perfect. 

Transparent 
to  opaque. 

B.  B.  fuses  (1.5)  and  colors  flame 
violet  ;  yields  water  in  closed  tube  ; 
reacts  for  fluorine. 

4-5- 

5- 

Brittle. 

2-3- 

2.4 

I.  Trapezohe- 
drons,  rarely 
massive. 

Cubic, 
In  traces. 

Transparent 
to  opaque. 

B.  B.  fuses  (2.5)  ;  water  in  closed 
tube. 

4-5 

Brittle. 

2- 
2.2 

III.  Always  in 
hexagonal 
crystals. 

Prismatic, 
perfect. 

Transparent 
to 
translucent. 

B.  B.  fuses  easily  (2.5-3)  with  intu- 
mescence; much  water  in  closed 
tube. 

B.  B.  fuses  with  intumescence  to  a 

4-5- 

Brittle. 

2- 
2.1 

III.  Rhombo- 
hedrons. 

Rhombohe- 
dral,  distinct. 

Iransparent 
to 
translucent. 

blebby  glass;  yields  water  in 
closed  tube;  decomposed  by  HC1 
without  gelatinizing. 

3-5- 
4. 

Brittle. 

2.2 

V.  Also 
globular  and 
granular. 

Clinopina- 
coidal, 
perfect. 

Transparent 
to  opaque. 

B.  B.  fuses  (2-2.5)  w^k  intumes- 
cence;  yields  water  in  closed 
tube;  decomposed  by  HC1  with- 
out gelatinizing. 

3-5- 
4- 

Brittle. 

2- 
2.2 

V.  Usually  in 
sheaf-like 
aggregates. 

Clinopina- 
coidal, 
perfect. 

Transparent 
to 
translucent. 

B.  B.  fuses  at  2.  5  with  intumescence; 
yields  water  in  closed  tube;  de- 
composed by  HC1  without  gelat- 
inizing. 

ir 

Brittle. 

2.6 

III.  Usually 
cleavable  or 
massive. 

Distinct. 

Transparent 
to  opaque. 

B.  B.  fuses  quietly  (3.5);  gelatin- 
izes with  HC1. 

5-5- 
6. 

Brittle. 

2-5 

I.  Trapezohe- 
drons,  rarely 
massive. 

None. 

Translucent 
to  opaque. 

B.  B.  infusible;  blue  color  with  cobalt 
solution  after  ignition;  insoluble. 

II.  Large 

5-6. 

Brittle. 

2-7 

crystals,  also 
cleavable  and 

Prismatic, 
distinct. 

Transparent 
to  opaque. 

B.  B.    fuses   readily    with    intumes 
cence  to  a  white,  blebby  glass. 

massive. 

5-6. 

Brittle. 

2.7 

VI.  Usually 
cleavable  or 

Basal  and 
pinacoidal, 

Transparent 
to 

B.  B.  fusible  with  difficulty;    insol 
uble 

massive. 

perfect. 

translucent. 

8o 


B.     MINERALS     WITHOUT 


Analytical  Key. 

Species. 

Composition 

Luster. 

Color. 

Streak. 

Micaceous  (perfect 
basal  cleavage). 
Folise  brittle. 

Chloritoid  (76). 

(FeMg)Al2 
Si06+H2O. 

Pearly. 

Dark  gray 
and  green- 
ish to  black. 

Grayish 
to  greenish. 

G   abov 

Reddish 

Light  brown 

Red  to  brown. 

Rutile  (26). 

Ti02. 

Adamantine. 

brown  to 

or   brownish 

Compare  Allanite. 

red. 

gray. 

Bladed  crystals, 

Blue  to 

with  blue 
centers  and 

Cyanite  (60). 
Compare  Tourma- 

Al2Si05. 

Vitreous 
to  pearly. 

white,  also 
green  and 

White. 

pale  margins. 

line. 

gray. 

Black  or 
nearly  black. 

Tourmaline 

(66). 

Complex 
silicate 
of  B,  Al,  etc. 

Vitreous. 

Usually 
black,  also 
red,  green, 
blue,  etc. 

White  to 
gray- 

p 

Compare  H. 
and  form. 

Amphibole 
(Hornblende) 

.    (50- 

(Ca,MgAl 
Fe)SiO3. 

Vitreous. 

Dark  green 
to  black. 

Greenish 
gray  to 

o 

[Compare  S.  T.  82.] 

1 

u 

'5 
a 

<u 

Fuse  with 

Epidote  (62). 

HCa2(Al, 
Fe)8Si8Oi8. 

Vitreous. 

Yellowish 
green  to 
dark  brown. 

Gray  to 
white. 

~z 

bfl 

intumes- 

0 

1. 

•2 

J 
us 

tt 

c 

cence. 

Vesuvianite 

(59)- 

Compare  S.  T.  77.] 

Ca12(Al 
Fe)6Si10O4i 
+2H20. 

Vitreous. 

Brown  to 
green. 

White. 

S 

J 

'column 

2$ 

it 

Infusible 
or  fuse 

Tourmaline 

(66). 

Complex 
silicate  of 
B,  Al,  etc. 

Vitreous. 

Black,  red, 
green, 
brown,  etc. 

White  to 
gray. 

•£ 

•— 

„ 

u 

So 

quietly. 

r^T 

8- 

Compare 

~ 

<* 

cd 

o 

o 

a 

H.  and 
form. 

Amphibole 

(Actinolite)  (49). 

Ca(MgFe)3 

Vitreous. 

Green  to 
gray. 

White. 

1 

ed 

a, 
u 

K 

B.  B.  infu- 
sible. 
Blue  color 

Diaspore  (29). 

A1203 
+H20. 

Pearly  to 
vitreous. 

White  to 
gray  and 
brown. 

White. 

with  cobalt 

g 

solution 

Brown  to 

—    H 
£    bJO 

after 

Sillimanite  (60). 

Al2SiO5. 

Vitreous. 

gray,  white, 

White. 

c 

|| 

ignition. 

Compare  Cyanite. 

green,  etc. 

^ 

<u 
B 

|| 

B.  B. 

fusible. 

Zoisite  (62). 

HCa2Al8 
Si3013. 

Vitreous 
to  pearly. 

Gray  to 
brown  and 
greenish  red. 

White. 

JS 

X 

* 

Compare 
intumes- 
cence. 

Amphibole 

(Tremolite)  (51). 

Compare  Hypers- 
thene  . 

CaMg3 
Si4O12. 

Vitreous 
to  silky. 

White  to 
gray. 

White. 

tO 

G.  above  2.75. 
Fusible. 

Amphibole  (51). 

(CaVtgAl 
Fe)Si03. 

Vitreous. 

White  to 
gray,  green, 
and  black. 

White  to 
gray. 

S 

O 

G.  below  2.75. 
Infusible. 

Quartz  (33). 

SiO2. 

Vitreous. 

Colorless, 
purple, 
smoky,  etc. 

White. 

METALLIC     LUSTER. 


81 


H 

Tenaci 

G 

Form. 

Cleavage 

Other 
Properties. 

Confirmatory  Chemical  Tests. 

6-5 

Lamin 
brittl 

3-5 

V.  or  VI. 

Coarsely 
foliated  or 
seal 

Basal, 

per  fee 

Pleochroic. 
Translucent 
to  opaque 

B.  B.  infusible;    becomes  dark  and 
magnetic;     yields  water  in  closed 
tube;    decomposed  by    sulphuric 
acid. 

1  1.  Prismatic  an 

6- 

6.5 

Brittle. 

4.2 

striated  crysta 
geniculated  an 

Prismatic, 
distinc 

Translucent 
to  opaque 

B.  B.  infusible;   insoluble. 

rosette  twin 

5- 
7.2 

Brittle. 

3-6 

VI.  Crystals 
coarsely  bladec 
rarely 
terminatec 

Pinacoidal 
perfee 
Angle— 
106 

Pleochroic. 
Translucent 
to 
transparent 

B.  B.  infusible;  insoluble;  the  pow- 
der ignited,  moistened  with  cobalt 
solution  and  ignited  again,assumes 
a  fine  blue  color. 

III.  Prismatic, 

7- 

7-5 

Very 
brittl 

3- 

3-2 

striated,  hemih 
dral  and 
hemimorphi 

None. 
Fracture 
uneve 

Transparent 
to  opaque 
Dichroic. 

B.  B.  mostly   infusible;     insoluble; 
gelatinizes  withHCl  after  ignition. 

5-6 

Brittle. 

3- 

3-5 

V.  Often  blade 
or  columna 

perfec 
Angles 

Pleochroic. 
Translucent 

B.  B.  fusible  (2.5-5)  '•>    insoluble. 

124°  ii 

to  opaque 

6-7 

Brittle. 

3-25 
3-5 

V.  Usually  pris 
made  and  stri 
ated,  also  acicu 
lar  and  fibrou 

Basal, 
perfet 

Pleochroic. 
Transparent 
to  opaque. 

B.  B.  fuses  (3-3.5)    with    intumes- 
cence to  a  magnetic  mass  ;  yields 
water  in  closed  tube  when  strong- 

I.  Prismatic 

C..U 

6.5 

Brittle. 

3-35 
3-45 

and  striated, 
also  columnar 
and  radiate 

Indistinct. 
'Yacture 
uneven 

translucen 
Slightly 
dichroi 

B.  B.  fuses  (3)   with   intumescence 
to  a  greenish  or  brownish  glass. 

7- 
7-5 

Very 
brittle 

;.2 

III.  Prismatic, 
striated,  hemi- 
hedral,  and 
hemimorphic 

Vone. 
'Yacture 
uneven 

fransparen 
to  opaque 
Dichroic. 

B.  B.  mostly    infusible;     insoluble; 
gelatinizes  with  HC1  after  fusion. 

V.  Often 

Prismatic, 

^leochroic. 

5-6 

Brittle. 

.2 

bladed  or 
columnar. 

perfect 
Angle= 

Yanslucent 
to 

B.  B.  infusible  (2.5-5);    insoluble. 

124°  n'. 

transparent. 

6-5 

7- 

^ery 
brittle. 

•3- 

•5 

V.  Usually 
}laded,  foliated, 
or  tabular. 

3rachypina- 
coidal, 
perfect. 

Yansparen 
to 
translucent 

B.  B.  infusible;   decrepitates  strong- 
ly ;   yields  water  at  a  high  temper- 
ature; blue  color  with  cobalt  solu- 

6-7. 

kittle. 

.2 

V.  Long,  slen- 
der crystals  to 
columnar 
and  fibrous. 

Srachypina- 
coidal, 
perfect. 

ometimes 
pleochroic. 
Yanslucent. 

tion  after  ignition;  insoluble. 
B.  B.  infusible;  insoluble;  the  pow- 
der ignited,  moistened  with  cobalt 
solution    and    ignited   again,   as- 
sumes a  fine  blue  color. 

6- 
6.5 

Brittle. 

•25 

•35 

V.  Slender 

rystals,  deeply 
striated,  also 
columnar. 

kachypina- 
coidal, 

perfect. 

ransparent 
to 
translucent. 
3leochroic. 

3.  13.    fuses    (3—  3-S)  with    intumes- 
cence to  a  white  blebby  mass;  gel- 
atinizes with   HC1  after  ignition; 
water  when  strongly  heated. 

5-6. 

rittle  to 
flexible. 

9- 
.1 

.  Usually 
aded,  fibrous, 
or  asbestiform. 

rismatic, 
perfect. 
ngle= 
124°  n'. 

Yanslucent 
to 
ransparent. 

S.  B.  fusible  (2.5-5);    insoluble. 

V.  Often 

i       i,     • 

5-6. 

rittle. 

9- 
5 

bkuled  or 
massive. 

rismatic, 
perfect. 

Yanslucent 
to  opaque. 

3.  B.  fusible  (2.5-5)  ;   insoluble. 

7- 

rittle. 

] 

65 

II.  Prisms, 
pyramids, 
and  massive. 

one. 
onchoidal 
fracture. 

"ransparent 
to  opaque. 

.  B.  infusible;   insoluble;  dissolve5 
with    effervescence    in    soda    on 
platinum  wire. 

82 


B.     MINERALS     WITHOUT 


Analytical  Key. 

Species. 

Composition         Luster. 

Color. 

Streak. 

j.  above  6. 

Cassiterite  (26). 

sno, 

Adamantine 
to  dull. 

3rown 
to  black. 

jray  to 
ight  brown. 

JU 

Isometric 
crystals, 

Garnet  (55). 

Complex 

Vitreous  to 

\.ed,  brown, 
yellow, 

White  to 

3 

sometimes 

Compare  Allantte 

silicate. 

resinous. 

white,  green, 

gray. 

* 

granular. 

and   Tephroite. 

black. 

m 
V 

I 

"rt 

j? 

1 

Adaman- 
tine luster. 
Vertically 
striated. 

Rutile  (26). 

no2. 

Adamantine. 

Reddish 
brown 
to  red. 

White  or 
gray  to 
pale  brown. 

<u  .g    . 

Adaman- 

3rown to 

a 

o 

tine  luster. 
Cryst.  usu- 
ally small. 

Brookite  (27). 

nog. 

Adamantine. 

yellowish, 
reddish 
and  black. 

White  to 
gray  or 
yellowish. 

S, 

Rough. 

Jray,  brown, 

ci. 

c 

hex.  cryst., 
massive  or 

Corundum  (25). 

A12O3.    , 

\damantine 
to  vitreous. 

red,  yellow, 
blue,  black, 

White. 

u 

granular. 

Compare  Emery. 

etc. 

1 

* 

White  to 
light  gray. 
Decrepitates. 

Diaspore  (29). 

+H20. 

Pearly  to 
•vitreous. 

White  to 
gray  and 
brown. 

White. 

K 

Q 

? 

Yellowish 

<J 
1 

Epidote  (62). 

HCa2(Al, 
Fe)3Si3Oi3. 

Vitreous. 

green  to 
dark  brown. 

Gray  to 
white. 

g 

r~ 

Fuse  with 

$ 

0 

1 

intumescence. 
Prismatic  and 
massive  forms. 

Vesuvianite 

(59)- 

Ca12(AlFe)6 
-MHio. 

Vitreous. 

Brown  to 
green. 

White. 

g 

^ 

D 

Compare  color. 

S 

1 

Q 
es 

Allanite  (62). 

Complex 
silicate. 

Submetallic 
to  resinous. 

Pitch  -brown 
to  black. 

Gray. 

i 

•o 

Compare  Pyroxene. 

g 

^/ 
~ 

c 

ft? 

Red,  brown, 

K  " 

.  * 

f! 

fsometric 
crystals  or 
granular 

Garnet  (55). 

Complex 
silicate. 

Vitreous  to 
resinous. 

yellow, 
white,  green, 
black 

White 
to  gray. 

£ 

^  "S 
<L>      • 

•lose-red 

Red  and 

'O 

o 

to  brown 
Usually 
massive 

Rhodonite  (50). 
[Compare  S.  T.7/.] 

MnSi03. 

Vitreous. 

brown  to 
gray. 

White. 

Prismatic 

simple  crys- 
als  or  cruci 

Staurolite  (66). 

MgFe2Al12 
Si6034 

Vitreous  to 
resinous. 

Dark  brown 
to  black 

White 
to  gray. 

•£>  S 

form  twins 

""£  ^ 

Octahedrons 

Black,  red, 

•—  '   o. 

g 

indirregula 

Spinel  (23). 

MgAl2O4. 

Vitreous. 

blue,  green, 

White. 

grains 

yellow,  etc 

g 

Deep  blue  or 

Turquois  (39). 

Al4P2On 
4-5  H20 

Waxy 
to  dull 

Sky-blue  to 
bluish  green 

White  to 
greenish. 

>luish  green 

_r: 

Compare  Lazurite  , 

• 

Sodalite  and 

o 

Labrador  He. 

Lazulite  (39). 

MgAl2P209 
-f-HoO 

Vitreous. 

Blue. 

\Vhite. 

METALLIC     LUSTER. 


H.    ^Tenacity 

G. 

Form. 

Cleavage. 

Other 
Properties. 

Confirmatory  Chemical   Tests. 

6-7. 

Brittle. 

6.8- 

11.  Simple  and 
twin  crystals, 
also  massive 

Imperfect. 
Fracture 

Translucent 
to  opaque. 

B.  B.  infusible;    yields  metallic    tin 
with  soda  on  charcoal;   insoluble. 

and  botryoidal. 

uneven. 

6.5- 

7-5 

Brittle. 

to 
4-3 

drons,  trapezo- 
hedrons;  also 
massive. 

None. 
Fracture 
uneven. 

Transparent 
to  opaque. 

B.  B.  fusible    (3-3.5),  usually  to   a 
magnetic  globule;  insoluble;  gel- 
atinizes with  HC1  after  fusion. 

II.  Prismatic  and 

Prismatic, 

6- 

6.5 

Brittle. 

4.2 

striated,  also 
geniculated  and 

distinct. 
Fracture 

Translucent 
to  opaque. 

B.  B.  infusible;   insoluble. 

rosette  twins. 

uneven. 

5-5- 
6. 

Brittle. 

3-9- 
4- 

IV.  Small  squar- 
ish crystals,  ver- 
tical faces  often 
striated. 

Imperfect. 
Fracture 
uneven. 

Translucent 
to  opaque. 

B.  B.  infusible;   insoluble. 

6-9- 

Brittle  to 
very 
tough. 

3-95 
to 
4.1 

III.  Crystals  of- 
ten rough  and 
rounded;  also 
massive. 

Basal  and 
rhombohe- 
dral  parting. 

Pleochroic. 
Transparent 
to  opaque. 

B.  B.  infusible;  insoluble;  fine  pow- 
der gives  blue   color  with  cobalt 
solution  after  long  heating. 

6.5- 

Very 
brittle 

3-3- 

IV.  Usually 
bladed,  foliated, 

Brachypina- 
coidal, 

Transparent 
to 

B.  B.  infusible  ;  decrepitates  strong- 
ly;   blue  color  with   cobalt  solu- 

7- 

3-5 

or  tabular. 

perfect. 

translucent 

tion  after  ignition;   insoluble. 

6-7. 

Brittle. 

3-25 
to 

3-5 

V.  Usually  pris- 
matic and  stri- 
ated, also  mas- 
sive, compact. 

Basal, 
perfect. 

Pleochroic. 
Transparent 
to  opaque 

B.  B.  fuses  (3—3.5)    with  intumes- 
cence to  a  black,  magnetic  mass; 
yields  water  in  closed  tube  when 
strongly  heated. 

6-5 

Brittle. 

3-35 
•to 
7.41: 

II.  Commonly 
prismatic  and 
terminated;  also 

Indistinct. 
Fracture 
uneven. 

Sub- 
translucent 
Slightly 

B.  B.  fuses  (3)  with  intumescence 
to  a  greenish  or  brownish  glass. 

massive. 

dichroic 

V.  Often  tabular 

, 

B.  B.  fuses  (2.5)  with  intumescence 

5;5~ 

Brittle. 

3-5- 
4.2 

or  prismatic,  also 
massive  or 

Fracture 

Opaque. 

to    a   magnetic   mass;     water   in 
closed  tube;     usually   gelatinizes 

granular. 

with  HC1. 

I.  Dodecahe- 

6.5- 

7-5 

Brittle. 

3.15 
to 

4-3 

drons,  trapezo- 
hedrons,  also 
granular. 

None. 
Fracture 
uneven. 

Transparent 
to  opaque. 

B.  B.  fusible  (3-3.5),  usually    to   a 
magnetic  globule;  insoluble;  gel- 
atinizes with  HC1  after  fusion. 

tr 

Brittle  to 
tough. 

3-4- 
3-7 

VI.  Crystals 
rare;  usually 
massive  to 

Prismatic, 
perfect. 
Fracture 

Translucent 
to  opaque. 
Blackens  on 

B.  B.   blackens   and   fuses   at    2.5; 
amethystine  bead  with  borax;   in- 

compact. 

uneven. 

exposure 

soluble. 

IV.  Prismatic, 

7- 
7-5 

Brittle. 

to 
3-75 

usually  in 
cruciform 
twins. 

Imperfect. 

Translucent 
to  opaque. 

B.  B.  infusible;   insoluble. 

I.  Octahedrons 

Octahedral. 

8. 

Brittle. 

3-5- 

and  water-worn 

Fracture 

I  ransparent 

B.  B.  infusible;   insoluble. 

4.1 

grains. 

conchoidal. 

6. 

Brittle. 

2.6- 

2.8 

Amorphous, 
incrusting, 
seams  and 

None. 
Fracture 
small 

Opaque. 

B.  B.  infusible;  yields  water  in  closed 
tube  and  turns  brown;   soluble  in 

grains. 

conchoidal. 

acid. 

B.  B.  infusible,  falls  to  pieces   and 

5-6. 

Brittle. 

3- 

V.  Octahedral, 
also  massive. 

Imperfect. 

Opaque. 

whitens;   blue  color  is  restored  by 
cobalt   solution;    yields  water  in 

closed  tube. 

B.     MINERALS     WITHOUT 


Analytical     Key. 

Species.              Composition 

Luster. 

Color. 

Streak. 

'1. 

k 

<5i 

| 

4.  Very  Hard.  —  Continued. 

00 
<N 

00* 

3J 

Yields  water  in 
closed  tube.j 

Opal  (34).             |Si02+H20. 

Vitreous 
to  resinous 
or  pearly. 

Various 
colors. 

White. 

OJ 

o 

Crystalline  or 
cleavable,  not 
amorphous. 

Wernerite  (58). 

CaAl2Si2O8. 

Vitreous. 

White,  gray, 
reddish,  etc. 

White. 

Vitreous  or  glassy. 
Jsually  black. 

Obsidian  (48). 

Like 
feldspar. 

Vitreous. 

Black  to 
dark  gray, 
red,  etc. 

White  to 
gray. 

tjj 

°3 
cr 

I 

Perfectly  compact 
or  felsitic. 

Felsite  (48). 

Like 
feldspar. 

Waxy 
to  dull. 

Red,  brown, 
greenish, 
gray,  black, 
etc. 

White  to 
gray. 

Crystalline  and 
cleavable  at  right 
angles  or  nearlyso. 
Distinctly 
scratched  by 
vitreous  quartz. 
Compare  also 
S.  T.  73,  75,  76-J 

§• 

P- 

w 

3 

Orthoclase 
and 
Albite. 

Oligoclase 
and 
Labradorite. 

Compare  Nephe- 
lite  smASntlalite. 

K2ALSi6 
016. 
Na2Al2Si6 

(Na2Ca)  A12 
"  Si6014. 
(Na2Ca)Al2 
Si3O10. 

Vitreous 
to  pearly. 

Vitreous 
to  pearly. 

White  to 
gray,  red, 
green,  etc. 

WThite,  gray 
to  greenish 
and  reddish. 

White. 
White. 

Infusible. 

Trapezohedrons. 
(24-sided 
crystals)  . 

Leucite  (49). 

KAlSi2O6. 

Vitreous. 

White  to 
gray. 

White. 

Vitreous  or  glassy. 

White  or 
colorless. 

Quartz  (Rock 
Crystal,  Vitreous, 
Milky,  etc.)  (33). 

Si02. 

Vitreous. 

WThite  or 
colorless. 

White. 

Purple, 
brown,  red, 
yellow,  etc. 

Quartz  (Ame- 
thyst, Smoky,  Fer- 
ruginous, etc.) 
(33)- 

SiO2. 

Vitreous. 

Purple, 
yellow, 
brown,  etc. 

White. 

Compact  or  cryptocrystalline, 
and  not  glassy. 

Translucent 
and  uni- 
formly 
colored. 

Quartz  (Chalced- 
ony, Carnelian, 
Chrysoprase, 
etc.)  (33). 

SiO2. 

Waxy. 

White,  gray, 
brown,  red, 
green,  etc. 

White. 

Translucent, 
and  banded, 
clouded,  etc. 

Quartz  (Agate, 
Onyx,  etc.)  (33). 

SiO2. 

Waxy. 

Same,  but 
banded, 
clouded,  or 
dendritic. 

White. 

Opaque,  and 
red,  brown, 
green,  etc. 

Quartz  (Jasper, 

etc.)  (33). 

SiO2. 

Waxy 
to  dull 

Red,  brown, 
yellow, 
green,  black, 
etc. 

White  to 
gray. 

Opaque  or 
nearly  so, 
and  black 
to  gray. 

Quartz  (Flint, 
Chert,  etc.)    (33). 

SiO2. 

Waxy 
to  dull 

Gray. 

brown, 
black. 

White  to 
gray. 

Purplish  red  flame 
(lithia). 

Spodumene 

(50)- 

LiAlSi2O6. 

Vitreous 
to  pearly. 

White  to 
gray  and 
green. 

White. 

Gelatinizes  with  HC1. 

Chondrodite 

034F4 

Vitreous 
to  resinous. 

Yellow,  red, 
brown,  to 
greenish 

White. 

METALLIC     LUSTER. 


H. 

Tenacity 

G. 

Form. 

Cleavage. 

Other 
Properties. 

Confirmatory  Chemical  Tests. 

if 

Brittle. 

1.9- 

2-3 

Amorphous. 
Sometimes 
botryoidal 
or  stalactitic 

None. 

Transparen 
to 
translucen 

B.  B.  infusible  ;  water  in  closed  tube  ; 
insoluble  in  acid;    soluble  in  caus- 
tic alkalies. 

5-6. 

Brittle. 

2.7 

II.  Large  crys- 
tals, also 
cleavable 
and  massive 

Prismatic, 
distinct 

Transparen 
to  opaque 

B.  B.  fuses  readily  with  intumescence 
to  a  white  blebby  glass;  insoluble. 

6. 

Brittle. 

2.2- 

2.8 

Amorphous, 
more  or  less 
glassy 

Fracture 
conchoidal 

Translucent 
to  opaque 

B.  B.  fuses    (3.5-4)    with   intumes- 
cence;  insoluble  in  acids. 

6. 

Brittle. 

2.4- 

2.8 

Amorphous 
or  felsitic,  often 
porphyritic 

Fracture 
even  to 
conchoidal 

Opaque. 

B.  B.  fusible,  but  not  easily;   insolu- 
ble in  acids. 

6- 
6-5 

6-7. 
5-6. 

Brittle. 
Brittle. 

2-5- 

2.05 

2.65 

-2.7 

V.  and  VI. 

Often  massive, 
or  lamellar 

VI.  Usually 
massive 

Basal  and 
clinopina- 
coidal, 
perfect 

Basal  and 
pinacoidal, 
perfect 

Transpareni 
to 
translucent 

Transpareni 
to 
translucent 

B.  B.  fusible  with  difficulty  (4-5)  ; 
insoluble. 

B.  B.  fusible  (3-3.5)  to  a  clear  glass; 
insoluble. 

5-5- 
6. 

Brittle. 

2-5 

[.  Trapezohe- 
drons,  rarely 
massive. 

None. 

Translucent 
to  opaque 

B.  B.  infusible  ;  blue  color  with  cobalt 
solution  after  ignition  ;    insoluble. 

7- 

Brittle. 

2.65 

[11.  Prisms  and 
3yramids,  and 
massive. 

STone. 

Transparent 
to  opaque 

B.  B.  infusible;  insoluble;  dissolves 
with  effervescence  in  soda  on  plat- 
inum wire. 

7- 

Brittle. 

2.65 

I.  II.  Prisms  and 
pyramids,  and 
massive. 

Mone. 

Transparent 
to  opaque. 

3.  B.  infusible;   insoluble;  dissolves 
with  effervescence  in  soda  on  plati- 
num wire. 

7- 

Brittle. 

2.6- 

2.65 

III.  Botryoidal, 
stalactitic,  etc. 

Conchoidal. 

Translucent. 

3.  B.  infusible  ;  insoluble;  dissolves 
with  effervescence  in  soda  on  plat- 
inum wire. 

7- 

Brittle. 

2.6- 

2.65 

[II.  Botryoidal, 
geoditic,  etc. 

Conchoidal. 

Translucent. 

Jke  chalcedony. 

7- 

Brittle. 

2.6- 

2.7 

'II.  Compact, 
banded,  etc. 

Conchoidal. 

Opaque. 

Jke  chalcedony. 

7- 

Brittle. 

2.6- 

2.7 

III.  Usually  in 
irregular 
nodules. 

Conchoidal. 

Translucent 
to  opaque. 

Jke  chalcedony. 

*>>s- 

7- 

Brittle. 

[.2 

V.  Prisms  and 
cleavable 
masses. 

3rismatic, 
perfect. 

"ranslucent 
to  opaque. 

5.  B.  fuses   (3.5)  with  purplish   red 
flame   and   intumescence;    insol- 
uble. 

6- 
6.5 

Brittle. 

i.2 

V.  Usually 
in  rounded 
grains. 

^one. 

"ranslucent 
to  opaque. 

5.B.  infusible;  gelatinizes  with  HC1; 
reaction   for  fluorine  with  potas- 
sium bisulphate  in  closed  tube. 

86 


B.     MINERALS     WITHOUT 


Analytical  Key. 

Species. 

Composition 

Luster. 

Color. 

Streak. 

Isometric 
crystals  or 
granular. 

Garnet  (55). 

Complex 
silicate. 

Vitreous 
to  resinous. 

Red,  brown, 
yellow, 
white,  green, 
black. 

White  to 
gray. 

Rose-  red 

Red  and 

Usually 

Rhodonite   (50). 

MnSiO3. 

Vitreous. 

brown  to 

White. 

J?> 

massive. 

.u 

Compact. 

— 

1) 
en 

Deep  green 
to  greenish 

Jadeite  (50). 

XaALSi2O6. 

Subvitreous. 

Green  to 
white. 

White. 

3 

white. 

Crystalline. 
White  to 
green  and 

Pyroxene  (50). 

(CaMgAl 
Fe)Si03. 

Vitreous. 

Green  to 
gray,  brown, 
black,  white 

White  to 
greenish 
gray. 

black. 

Green  to 

T 

[Compare 
S.  T.  77,  78.1 

Amphibole  (51). 

Compare    Tourma- 
line, Hyperstlicne. 

(CaMgAl 
Fe)SiO3. 

Vitreous. 

white,  gray, 
brown, 
black. 

White  to 
greenish 
gray. 

jy 

| 

'% 

Green  to 
gray. 

Prehnite  (64). 

H2Ca2Al2Si3 
012. 

Vitreous. 

Green  to 
gray. 

White. 

1 
\ 

I 

00 

ci 

§ 

"scence. 

G.  below  3.  2. 
Green,  red, 
brown. 

Tourmaline 

.       (66). 

Complex 
silicate  of 
B,  Al,  etc. 

Vitreous. 

Black,  red, 
green,  blue, 
etc. 

White  to 
gray. 

L. 

ft. 

( 

rt 

i  intumt 

Epidote  (62). 

HCa2(Al 

Fe)3Si2Oi3. 

Vitreous. 

Yellowish 
green  to 
dark  brown. 

Gray  to 
white. 

03 

*-* 

PO 

4-1 

Prismatic 

£ 

^ 

5 

3 

> 

<u 

g 

and  colum- 
nar forms, 
to  massive. 

Vesuvianite 

(59)- 

Ca12(Al, 
te)6Si10O4i 
+2H20. 

Vitreous. 

Brown  to 
green. 

White. 

JO 

"•H 

rj 

Compare 

ftg 

colors. 

Gray  to 

Zoisite  (62). 

Compare 

HCa2Al3Si3 

Vitreous 
to  pearly. 

brown, 
greenish 

White  to 
gray. 

S.T.  42.51,82,  88.] 

and  red 

First  ignited  B. 
B.,  then  moist- 
ened with  cobalt 

Diaspore  (29). 

Al2O3-f 
H2O. 

Pearly 
to  vitreous. 

White  to 
gray  and 
brown. 

White. 

solution  and  ig- 

nited again,  as- 
sume a  beautiful 
blue  color. 

Andalusite  (60). 

Al2Si05. 

Vitreous 
to  dull. 

White,  gray, 
red,  green, 
brown. 

White  to 
gray. 

V 

—• 

Green. 
Small, 
crystalline 

Chrysolite  (56). 

(MgFe>Si 
04. 

Vitreous. 

Green. 

White. 

iS 

grains. 

STot  belonging  to 
the  foregoing. 

Tourmaline 

(66). 

Complex 
silicate  of 
B,  Al,  etc. 

Vitreous. 

Black,  red, 
green,  blue, 
etc. 

White  to 
gray. 

Compare  H.  and 
cleavage. 
Compare  S.  T. 
86,  87,  98.] 

Amphibole 
(llornbl'de)(5i). 
Pyroxene 

(CaMgAl 
Fe)SiO3. 

Vitreous. 

Dark  green 
to  black. 

Greenish 
gray. 

(Augite)  (50). 

METALLIC     LUSTKR. 


H. 

Tenacity      G.                 Form. 

Cleavage. 

Other 
Properties. 

Confirmatory  Chemical  Tests. 

I    Dodecahe- 

6.5- 

7-5 

Brittle. 

3-15 
-4-3 

drons,  trapezo- 
hedrons;  also 

None. 
Fracture 
uneven. 

Transparent 
to  opaque. 

B.  B.  fusible  (3-3.5),  usually  to  a 
magnetic  globule;  insoluble;  gel- 
atinizes with  HC1  after  fusion. 

granular  mas've 

5-5- 
6.5 

Brittle 
to  tough 

34- 
3-7 

VI.  Crystals 
rare,  usually 
massive  or 

Prismatic, 
perfect. 
Fracture 

Transparent 
to  opaque. 
Blackens  on 

B.  B.  blackens  and  fuses  at  2.5  ;  am- 
ethystine bead  with  borax;  insol- 

compact 

uneven. 

exposure. 

6.5- 

7- 

Very 
tough 

3-3 

Massive  or 
compact 

Splintery. 

Translucent. 

B.  B.  fuses  readily  to  a  transparent 
blebby  glass;  not  affected  by 
acids. 

V.  Crystals  com- 

Prismatic, 

5-6. 

Brittle. 

3- 
3-5 

mon,  but  often 
massive  and 

perfect. 
Angles 

Transparent 
to  opaque. 

B.  B.  fusible  (2.5-5)  '•>   insoluble. 

granular 

87°  5'. 

5-6- 

Brittle. 

29- 
32 

V.  Crystals  com- 
mon, 'out  often 
bladed  or 

Prismatic, 
perfect. 
Angles 

Transparent 
to  opaque. 
Dichroic. 

B.  B.  fusible  (2.5-5);   insoluble. 

massive 

124°  ll'. 

IV.  Distinct 

B.  B.  fusible  (2)  with  intumescence 

6- 
6.5 

Brittle. 

2.8- 

2-95 

crystals  rare, 
often  with 

Basal, 
distinct. 

Translucent. 

to  a  blebby  glass;  yields  water  in 
closed  tube;  gelatinizes  with  HC1 

crested  surface 

after  fusion. 

7- 
7-5 

Very 
brittle 

3- 

3-2 

III.  Prismatic, 
striated,  hemihe- 
dral,  hemimor- 
phic;  rarely  mas 

None. 
Fracture 
uneven  . 

Transparent 
to  opaque. 
Dichroic. 

B.  B.  mostly  infusible;  insoluble; 
gelatinizes  with  HC1  after  fusion. 

6-7. 

Brittle. 

3-25 
-3-5 

V.  Usually  pris- 
matic and  striat- 
ed, also  acicular 
and  compact. 

Basal, 
perfect 

Pleochroic. 
Transparent 
to  opaque. 

B.  B.  fuses  (3—3.5)  with  intumes- 
cence to  a  magnetic  mass;  yields 
water  in  closed  tube  when  strongly 
heated. 

II.  Prismatic 

• 

Sub- 

6-5 

Brittle. 

3-35 

3-45 

and  striated, 
also  columnar 

P'racture 

translucent. 
Slightly 

B.  B.  fuses  (3)  with  intumescence  to 
a  greenish  or  brownish  glass. 

and  radiate. 

dichroic. 

IV.  Slender 

Transparent 

6- 
6-5 

Brittle. 

3-25 
3-35 

crystals,  deeply 
striated,  also 
columnar. 

pinacoidal, 
perfect. 

to 
translucent. 
Pleochroic. 

B.  B.  fuses  (3-3.5)  with  intumes- 
cence to  a  white,  blebby  mass. 

6.5- 
7- 

Very 
brittle. 

3-3- 
3-5 

IV.  Usually 
Waded,  foliated 
or  tabular. 

Brachy- 
pinacoidal, 
perfect. 

Transparent 
to 
translucent. 

B.  B.  infusible  ;  decrepitates  strongly, 
yields  water  at  a  high  temperature; 
blue  color  with  cobalt  solution 
after  ignition;  insoluble. 

6- 

7-5 

Brittle. 

3-i5 
-3-2 

IV.  Square 
prisms,  usually 
black  square  or 
cross  on  section. 

Imperfect. 
Fracture 
uneven. 

Pleochroic. 
Transparent 
to  opaque. 

B  B.  infusible;  insoluble;  blue  color 
with  cobalt  solution  after  ignition. 

6.5- 

7- 

Brittle. 

3-3- 

3-4 

IV.  Usually  in 
grains  or 
granular. 

Fracture, 
conchoidal. 

Transparent 
to 
translucent. 

B.  B.  infusible;  gelatinizes  with  HC1. 

7- 
7-5 

Very 
brittle. 

3- 

3-2 

III.  Prismatic, 
striated,  hemihe- 
dral,  hemimor- 

None. 
Fracture 
uneven. 

Transparent 
to  opaque. 
Dichroic. 

3.  B.   mostly  infusible;     insoluble; 
gelatinizes  with  HC1  after  fusion. 

>mc,  rarely  mas. 

V.  Crystals 

Prismatic, 

Opaque  to 

5-6. 

Brittle. 

3- 

3-5 

common,  hut 
often  massive 

perfect. 
124°  ll', 

translucent. 
Dichroic  and 

B.  B.  infusible  (5)  or  nearly  so;  in- 
soluble. 

or  bladed. 

87°  5'. 

non-dichroic 

B.     MINERALS     WITHOUT 


Analytical  Key. 

Species. 

Composition 

Luster. 

Color. 

Streak. 

||  V.  Streak  White  or  Gray.—  Continued. 

5.  Adamantine. 

G.  above  6. 

Cassiterite  (26). 

SnO2. 

Adamantine 
to  dull. 

Brown  to 
black,  etc. 

White  to 
gray. 

fO 

| 

^o 

""w 

Ja 

0 

Green  to   bluish 
green  and 
yellowish 
green. 

Beryl  (52). 

Be3Al2Si6 

Ol8- 

Vitreous. 

Green  to 
bluish  and 
yellowish 
green. 

White. 

Colorless,  pur- 
ple, smoky, 
brown,  etc. 
Rarely  green. 

Quartz  (Rock 
Crystal,  Amethyst, 
Smoky,  Ferrugi- 
nous, etc.)  (33). 

SiO2. 

Vitreous. 

Colorless, 
purple,  yel- 
low, brown, 
etc. 

White. 

G.  below  3.25. 
Compare  Chrysolite. 

Square  or 
rectangular 
prisms. 

Andalusite  (60). 

Al2SiO5. 

Vitreous 
to  dull. 

White,  gray, 
red,  green, 
brown. 

White. 

Sub-triangular, 
striated  prisms, 
terminated  by 
rhombohedrons. 

Tourmaline 

(66). 

Complex 
silicate. 

Vitreous. 

Black,  red, 
green,  blue, 

etc. 

White  to 
gray. 

IT.  10,  scratches 
corundum. 
G.  3-5- 

Diamond  (5). 

C. 

Adamantine, 
often 
brilliant. 

Colorless  to 
yellowish, 
reddish,  etc. 

White. 

Fusible. 
Isometric. 
Red,  brown,  etc. 

Garnet  (55). 

Complex 
silicate. 

Vitreous. 

Red,  brown, 
yellow, 
white,  green, 
black. 

White. 

Distinct  tetragonal 
prisms  and  pyramids. 
G.  above  4. 

Zircon  (26). 

ZrSiO4. 

Adamantine. 

Gray,  yel- 
lowish, 
brownish, 
etc. 

White. 

Distinct  octahedrons, 
and  colored  grains. 
G.  above  3.5. 

Spinel  (23). 

MgAl204. 

Vitreous. 

Black,  red, 
blue,  green, 
yellow,  etc. 

White. 

jD 

"o 

0 

1> 

3 
—  <    C 

-°  2 

si 

*  s 

OS  ^ 

<u  "« 

>  ^2 

a  3 

o-fl 

11 

.5f> 

14 

OJ 

3 

G.  about  4. 
11.  9. 

Corundum  (25). 
Compare  Emery. 

A12O3. 

Adamantine 
to  vitreous. 

Gray,  brown, 
red,  yellow, 
blue,  etc. 

White. 

Green. 
Tabular  twin 
crystals. 

Chrysoberyl 

(24). 

BeAl2O4. 

Vitreous. 

Green, 
various 
shades. 

White. 

Prismatic  crys- 
tals with  perfect 
basal  cleavage. 

Topaz  (60). 

Al2SiO4F2. 

Vitreous. 

Yellow, 
white,  blue, 
red,  green, 
etc. 

White. 

Bladed  crystals, 
with  blue  cen- 
ters and  pale 
margins. 

Cyanite  (60). 

Compare  Silliman- 
ite,  Diaspore,  Topaz. 

Al2SiO5. 

Vitreous 
to  pearly. 

Blue  to 
white,  also 
green  and 
gray. 

White. 

G.  below  3.5. 
Green,  crystalline 
grains. 

Chrysolite  (56). 

(MgFe)2 
Si04. 

Vitreous. 

Green. 

White. 

G.  above  3.5. 
Prismatic  crystals  and 
cruciform  twins. 

Staurolite  (67). 
Compare  Epidote, 
Jadeite  ,  Spodu  mene. 
[Compare  also  S.  T. 
27,83,85,86.] 

MgFe2Ali2 
Si6034. 

Vitreous 
to  resinous. 

Dark  brown 
to  black. 

White  to 
gray. 

METALLIC     LUSTER. 


89 


H. 

6-7. 

Tenacity 

G. 

Form. 

Cleavage. 

Other 
Properties. 

Confirmatory  Chemical  Tests. 

Brittle. 

6.8- 
7-1 

II.  Simple  and 
twin  crystals, 
botryoidal, 
and  massive. 

Indistinct. 
Fracture 
uneven. 

Translucent 
to  opaque. 

B.  B.  infusible;  insoluble;  tin  with 
soda  on  charcoal. 

I5' 

Brittle. 

2.7 

III.  Hexagonal 
prisms,  rarely 
massive  . 

Imperfect. 
Fracture 
conchoidal 
to  uneven. 

Transparent 
to 
translucent. 
Dichroic. 

B.  B.  infusible;   insoluble. 

7- 

Brittle. 

2.65 

III.  Prisms  and 
pyramids, 
also  massive. 

None. 
Fracture 
conchoidal. 

Transparent 
to  opaque. 

B.  B.  infusible;  insoluble;  dissolves 
with  effervescence  in  soda  on  plat- 
inum wire. 

7-5 

Brittle. 

3.15 
-3-2 

3- 
3-2 

IV.  Square 
prisms,  usually  a 
black  square  or 
cross  on  section. 

Imperfect. 
Fracture 
uneven. 

Transparent 
to  opaque. 
Pleochroic. 

B.  B.  infusible;  insoluble;  gives  a 
blue  color  with  cobalt  solution  after 
ignition. 

7- 

7-5 

Very 
brittle. 

III.  Striated 
pi  isms,  hemihe- 
dral,  hemimor- 
phic,rarely  m've. 

None. 
Fracture 
uneven. 

Transparent 
to  opaque. 
Dichroic. 
Pyroelectric. 

B.  B.  mostly  infusible;  insoluble; 
gelatinizes  with  HC1  after  ignition. 

10. 

Brittle. 

3-5 

I.  Octahedrons, 
etc.,  usually  with 
curved  faces. 

Octahedral, 
perfect. 

Transparent 
to 
translucent. 

B.  B.  infusible  ;  burns  at  a  high  tem- 
perature; insoluble. 

6.5- 
7-5 

7-5 

Brittle. 

3-5- 
4-3 

I.  Dodecahe- 
drons, trapezo- 
hedrons,  also 
granular  m's've. 

Imperfect. 
Fracture 
uneven. 

Transparent 
to  opaque. 

B.  B.  fusible  (3-3.5)  ;  usually  to  a 
magnetic  globule;  insoluble;  gel- 
atinizes with  HC1  after  fusion. 

Brittle. 

4.2- 
4-8 

II.  Square 
prisms  and  pyr- 
amids, rarely 
irregular  grains. 

Imperfect. 
Fracture 
uneven. 

Transparent 
to  opaque. 

B.  B.  infusible  ;   insoluble. 

8. 
9- 

Brittle. 

3-5- 
4.1 

I.  Octahedrons 
and  water-worn 
grains. 

Octahedral, 
imperfect. 

Transparent 
to  opaque. 

B.  B.  infusible;   insoluble. 

Brittle 
to  very 
tough. 

395 
to 
4.10 

III.  Rough,  hex- 
agonal crystals, 
also  massive  to 
finely  granular. 

Basal  and 
rhombohe- 
dral. 

Transparent 
to  opaque. 
Pleochroic. 

B.  B.  infusible;  insoluble;  gives  a 
blue  color  with  cobalt  solution 
after  ignition. 

8.5 

Brittle. 

3-5- 

3-«5 

IV.  Usually  in 
tabular,  hexag- 
onal twins. 

Imperfect. 

Transparent 
to 
translucent. 
Pleochroic. 

B.  B.  infusible;  insoluble;  gives  a 
blue  color  with  cobalt  solution 
after  ignition. 

8. 

Brittle. 

3-4- 
3-65 

IV.  Rhombic 
prisms,often  stri- 
ated, with  pyra- 
mids and  domes. 

Basal, 
perfect. 

Transparent 
to  opaque. 

B.  B.  infusible;  insoluble;  blue  col- 
or with  cobalt  solution  after  igni- 
tion; fluorine  reaction. 

5- 
7-25 

Brittle. 

3-6 

VI.  Crystals 
coarsely  bladed, 
rarely 
terminated. 

Pinacoidal, 
perfect. 

Transparent 
to 
translucent. 
Pleochroic. 

B.  B.  infusible;  insoluble;  blue  col- 
or with  cobalt  solution  after  igni- 
tion. 

6.5- 
7- 

Brittle. 

3-3- 
3-4 

IV.  Usually 
in  grains  or 
granular. 

Fracture 
conchoidal. 

Transparent 
to 
translucent. 

B.  B.  infusible;  gelatinizes  with  HC1. 

7- 
7-5 

Brittle. 

3-6 

[V.  Prismatic, 
usually  in 
cruciform  twins. 

[mperfect. 

Translucent 
to  opaque. 
Pleochroic. 

B.  B.  infusible;   insoluble. 

9° 


SUPPLEMENTARY 


No 

I 

Species. 

Composi- 
tion 

Luster. 

Color. 

Streak. 

H. 

Tenacity. 

G 

Platinum  (2). 

Pt. 

Metallic. 

Whitish  steel-gray. 

Dark  gray. 

4- 
4-5 

Malleable 
and  ductile. 

14- 

22. 

2 

Iridosmine  (2). 

Ir,Os. 

Metallic. 

Tin-white  to  light 
steel-gray. 

Gray. 

6-7. 

Slightly 
malleable. 

19-3- 
21.12 

3 

Tellurium  (3). 

Te. 

Metallic. 

Tin-white. 

Gray. 

2- 

2-5 

Somewhat 
brittle. 

6.1- 
6-3 

A 

Hessite  (6). 

Ag.2Te. 

Metallic. 

Between  lead-gray 
and  steel-gray 

Black. 

2-5- 
3- 

Somewhat 
sectile. 

8-3- 
8.9 

i 

Petzite  (6). 

(Ag,Au)2 
Te. 

Metallic. 

Steel-gray  to 
iron-black. 

Black. 

2-5- 

3- 

Slightly 
sectile. 

8.7- 
9- 

6 

Altaite  (6). 

PbTe. 

Metallic. 

Yellowish  tin-white. 

Gray. 

3- 

Sectile. 

8.15 

7 

Stromeyerite 

(7)- 

(AgCu)2S. 

Metallic. 

Dark  steel-gray. 

Black. 

2-5- 
3- 

Brittle. 

6.15- 
6-3 

8 

Metacinnabarite 

(8). 

HgS. 

Metallic. 

Grayish  black. 

Black. 

3- 

Brittle. 

7.8 

9 

Tiemannite  (8). 

HgSe. 

Metallic. 

Steel-gray  to 
blackish  lead-gray. 

Black. 

2-5 

Brittle. 

8.2 

10 

Covellite  (9). 

CuS. 

Submetallic 
to  resinous. 

Indigo-blue  or  darker. 

Dark  gray 
to  black. 

'•5- 

2. 

Flexible  in 
thin  leaves. 

4.6 

ii 

Greenockite  (9). 

CdS. 

Adamantine 
to  resinous. 

Yellow,  various 
shades. 

Orange  to 
brick  red. 

3~ 
3-5 

Brittle. 

4-9- 

5- 

12 

Stannite  (10). 

Cu2FeSn 
S4. 

Metallic. 

Steel-gray  to 
iron-black. 

Black. 

4- 

Brittle. 

4-3- 
4-5 

13 

Gersdormte 

(10). 

NiAsS. 

Metallic. 

Silver-white  to 
steel-gray. 

Dark  grayish 
black. 

5-5 

Brittle. 

5.6- 

6.2 

14 

Nagyagite  (12). 

AuPbFeS. 

Metallic, 
splendent. 

Blackish  lead-gray. 

Black. 

r-5 

Thin  laminae 
flexible. 

6.85- 

7-2 

15 

Kermesite  (14). 

Sb2S2O. 

Adamantine 

Cherry-red. 

Brownish  red. 

i-5 

Sectile. 

tr 

16 

Zinkenite  (16). 

PbSb2S4. 

Metallic. 

Steel-gray. 

Dark  gravish 
.black. 

3~ 
3-5 

Brittle. 

5-3- 
5-35 

i? 

Berthierite  (16). 

FeSb2S4. 

Metallic. 

Dark  steel-gray 
to  brown. 

Nearly  black. 

2-3- 

Brittle. 

4- 
4-3 

18 

Cosalite  (16). 

Pb2Bi2S5. 

Metallic. 

Lead-gray  to 
steel-gray. 

Black. 

2-5- 
3- 

Brittle. 

6.4- 
6-75 

19 

Freieslebenite 

(i  6). 

(Pb,Ag2)5 
Sb4Sn. 

Metallic. 

Light  steel-gray  to 
silver-white. 

Nearly  black. 

2-5 

Rather 
brittle. 

6.2- 

6.4 

20 

Boulangerite 
(Id). 

Pb3Sb2S6. 

Metallic. 

Bluish  lead-gray. 

Nearly  black. 

2-5- 
3- 

Brittle. 

5-75- 

6. 

21 

Polybasite  (16). 

Ag9SbS6. 

Metallic. 

Iron-black. 

Black. 

2-3- 

Brittle. 

6- 

6.2 

22 

Sylvite  (17). 

KC1. 

Vitreous. 

Colorless,  white, 
bluish,  etc. 

White. 

2. 

Brittle. 

2. 

23 

24 

25 

Embolite  (17). 
Bromyrite  (17^). 
[odyrite  (17). 

Ag(ClBr). 
AgBr. 
Agl. 

Resinous. 

Resinous  to 
adamantine. 

Resinous  to 
adamantine. 

Green  to  yellow. 

Bright  yellow  to 
greenish. 

Yellow  to  green 
or  brown. 

Greenish  or 
yellowish. 

Yellow  to 
greenish. 

Yellow. 

I- 

i-5 

2-3- 

Soft. 

Sectile  or 
waxy. 

Sectile  or 
waxy. 

Sectile  and 
flexible. 

5-3- 
5.8 

5.8- 
6. 

5.6- 
5-7 

TABLE. 


Form. 

Cleavage. 

Other 

Properties. 

Confirmatory  Chemical  Tests. 

I.  Crvstals  rare;    usually 

None. 

Opaque.  Often 

B.  B.  infusible;   soluble  only  in  hot  aqua  regia. 

in  grains  or  nuggets. 

magnetic. 

III.  Ilex,  prisms  rare;  us- 
ually irregular  grains. 

Basal, 
perfect 

Opaque. 

B.  B.  infusible;   insoluble. 

III.  Usually  massive;  also 
columnar. 

Prismatic, 
perfect. 

Opaque. 

B.  B.  on  charcoal  fuses  easily  and  volatilizes,  giving  white 
coating;   white  sublimate  in  open  tube. 

I.  Distorted  crystals;  also 
massive  to  compact. 

Fracture, 
even. 

Opaque. 

B.  B..on  charcoal  fuses  easily  to  a  black  globule;  globule 
of  silver  with  soda. 

Massive  to  compact. 

Fract.  sub- 
conchoidal. 

Opaque.  Often 
tarnishes. 

Like  hessite;   but  yields  globule  containing  both  gold  and 
silver. 

I.  Usually  massive;  rare- 
ly in  cubes. 

Fract.  sub- 
conchoidal. 

Opaque.  Tar. 
to   bronze-yel. 

B.  B.  on  charcoal  fuses  easily  and  volatilizes,  giving  me- 
tallic and  yellow  coatings;  white  sublimate  in  open  tube. 

IV.  Prismatic  crystals;  al- 
so massive  to  compact. 

Fract.  sub- 
conchoidal. 

Opaque. 

B.  B.  fuses  easily,  on  charcoal,  to  a  semi-malleable  glob- 
ule; reactions  for  sulphur,  soluble  in  HNO3. 

I.  Tetrahedral;  also  mas- 

Fracture, 

Opaque. 

B.  B.  volatile;  with  soda  in  closed  tube  yields  sublimate  of 

sive  to  compact. 

uneven. 

mercury. 

I.  Tetrahedral;  common- 
ly massive  to  compact. 

None.  Fract. 
conchoidal. 

Opaque. 

B.  B.  on  charcoa1,volatilizes,  giving  a  lustrous  metallic  coat- 
ing; in  closed  tube  decrepitates,  forming  black  sublimate. 

III.  Rarely  in  hex.  crys- 
tals;   commonly  massive. 

Basal, 
perfect. 

Opaque. 

B.  B.  on  charcoal  burns  with  a  blue  flame,  and  fuses  to  a 
globule;   sulphur  sublimate  in  closed  tube. 

III.  Hemimorphic;  usual- 
ly massive  or  incrusting. 

Distinct. 
Conchoidal. 

Transparent 
to  opaque. 

B.  B.  infusible;   reddish  brown  coating  on  charcoal;   sul- 
phurous fumes,  soluble  in  HC1,  evolving  H2S. 

Massive,    granular,    and 
disseminated  grains. 

Cubic, 
indistinct. 

Opaque. 
Bluish  tarnish. 

B.  B.  fuses  and  gives  coating  of  SnO2  on  charcoal;    de- 
crepitates;  sulphur  fumes. 

I.  Pyritohedral,  also  lam- 
ellar and  massive. 

Cubic,  rather 
perfect. 

Opaque. 

B.  B.  decrepitates  and  fuses  to  a.  globule,  evolving  sulphu 
rous  and  arsenical  fumes;  white  sublimate  in  open  tube. 

IV.  Tabular  crystals,  gen- 
erally foliated,  massive. 

Brachypina- 
coid,  perfect. 

Opaque. 

B.  B.  on  charcoal  fuses  and  forms  yellow  and  white  coat- 
ings; gray  and  white  sublimates  in  open  tube. 

V.  Usually  in  tufts  of  cap- 
illary crystals. 

Pinacoidal, 
perfect. 

Translucent 
to  opaque. 

B.  B.  fuses  easily;  white  fumes  and  coating  on  charcoal; 
white  sublimate  in  tube. 

IV.  Usually  columnar,  fi- 
brous, massive. 

Fracture, 
uneven. 

Opaque. 

B.  B.  decrepitates,  fuses  and  volatilizes,  forming   yellow 
and  white  coatings  and  sublimates. 

Elongated    prisms,    also 
ribrous  to  granular. 

Longitudi- 
nal, indist. 

Opaque.  4 
Tarnishes. 

B.  B.  on  charcoal,  fuses,  white  coating  and  fumes;    mag- 
netic residue;   white  sublimate  in  open  tube. 

IV.  Usually  massive  some- 
times fibrous,  radiated. 

Fracture, 
uneven. 

Opaque. 

B.  B.  fuses  easily,  giving  sulphur  fumes  and  yellow  coating 
on  charcoal. 

V.  Prismatic  crystals,  ver- 
tically striated. 

Prismatic, 
imperfect. 

Opaque. 

B.  B.  fuses  easily,  giving  yellow  and  white  coatings  and  sul- 
phur fumes;   white  sublimate  in  open  tube. 

Plumose     masses,      also 
granular  and   compact. 

Fracture, 
uneven. 

Opaque.    Tar- 
nishes yellow. 

B.  B.  decrepitates,  fuses  and  volatilizes,  forming  yellow 
and  white  coatings  and  sublimates. 

IV.  Short,  six-sided,  tab- 
ular prisms. 

Basal, 
imperfect. 

Cherry-red  by 
transm'd  light. 

B.  B.  fuses  with  spirting,  giving  white  coating  and  subli- 
mate. 

I.  Cubic     crystals;      also 
massive. 

Cubic, 
perfect. 

Transparent 
to  translucent. 

B.  B.  fuses;  violet  flame;  reactions  for  chlorine;  very  sol- 
uble in  water. 

I.  Usually      massive     or 
compact. 

Fracture, 
uneven. 

Transparent 
to  translucent. 

B.  B.  fuses  and  gives  globule  of  Ag.  ;  yields  brown  bromine 
vapors  when  fused  with  HKSO4  in  closed  tube. 

I.  Crystals  rare;   in  small 
concretions. 

Fracture, 
uneven. 

Transparent 
to  translucent. 

Like  embolite,  but  no  reactions  for  chlorine. 

III.  Hemimorphic;     also 
massive  and  lamellar. 

Basal, 
perfect. 

Translucent. 

B.jB.  fuses  and  gives  globule  of  Ag.;  yields  violet  iodine  va- 
pors when  fused  with  HKSO4  in  closed  tube. 

92 


SUPPLEMENTARY 


No 

Species. 

Composition. 

Luster. 

Color. 

Streak. 

H.          Tenacity. 

G 

26 

Massicot  (21). 

PbO. 

Dull. 

Yellow. 

Lighter 

2. 

Earthy. 

7.8- 

yellow 

8. 

27 

Gahnite  (23). 

ZnAl2O4. 

Vitreous. 

Dark  green  to 

Grayish. 

7-5- 

Brittle. 

4- 

black 

8. 

4.6 

28 

Hausmannite 

Mn3O4. 

Submetallic 

Brownish  black. 

Chestnut- 

5- 

Brittle. 

4-7- 

(23) 

brown 

5-5 

4.85 

29 

Minium  (23). 

Pb304. 

Dull. 

Brick-red  with 
yellow 

Orange- 
yellow 

2-3- 

Earthy. 

4.6 

3° 

Octahedrite 

(27) 

Ti02. 

Adamantine 
to  metallic 

Brown  to  black. 

Gray. 

Is- 

Brittle. 

3-8- 
4-15 

31 

Bauxite  (30). 

A1203+ 
2H2O 

Dull. 

Whitish  to  red, 
yellow  or  brown 

Like  color. 

Brittle  to 
earthy 

2-5 

32 

Arsenolite  (32a) 

As2O3. 

Vitreous 
or  silky 

White. 

White. 

l-S 

Brittle. 

3-7 

33 

Senarmontite 

Sb2O3. 

Resinous. 

Colorless  to  gray. 

White. 

2- 

Brittle. 

5-2- 

(3*0 

2-5 

5-3 

34 

Valentinite 
(3*0 

Sb2O3. 

Adamantine 
to  pearly 

White  to  red, 
gray  or  brown 

White. 

2-5- 
3- 

Brittle. 

5-5 

35 

Stibiconite 

H2Sb205. 

Pearly  to 

Pale  yellow  to 

White. 

4- 

Brittle. 

5-1- 

(3*0 

earthy 

white 

5-5 

5-3 

36 

Polycrase  (35). 

Complex 

Vitreous 

Black. 

Grayish 

5-6. 

Brittle. 

5- 

niobate,  etc 

to  resinous 

brown 

37 

Xenotime  (37a) 

YPQ4. 

Resinous  to 

Brown,  to  red, 

Pale  brown, 

4-5- 

Brittle. 

4-45- 

vitreous 

yellow,  white,  etc 

yellowish,  etc 

4-55 

38 

Triphylite  (37a) 

LiCFeMn^) 
P04 

Vitreous 
to  resinous. 

Greenish  gray,blu- 
sh,  yellow,  brown. 

White. 

4-5- 

5' 

Brittle. 

3-4- 
3-55 

39 

Beryllonile 

NaBePO4. 

Vitreous, 

Colorless,  to  white. 

White. 

5-5- 

Brittle. 

2.8 

(37^). 

brilliant. 

x 

40 

Herderite  (37a). 

(CaF)BePO4. 

Vitreous. 

Yellowish  and 

White. 

Brittle. 

3- 

greenish  white. 

4i 

Triplite  (37a). 

(FeMn)F-f 
(FeMn)PO4. 

Resinous. 

3rown  to  black. 

Yellowish  gray 
or  brown. 

4~ 

5-5 

Brittle. 

3-45- 
3.8 

42 

Amblygonite 

Li(AlF)PO4. 

Vitreous 

White  to  nearly 

White. 

6. 

brittle. 

3- 

(37*)- 

to  greasy. 

white. 

l-i 

43 

Olivenite  (37a). 

Cu3As2O8-f- 

Adamantine 

Green  to  black 

Olive-green 

Brittle. 

4.1- 

Cu(OH)2. 

to  vitreous. 

and  brown. 

to  brown. 

•4 

44 

Descloizite 
(37*)- 

(PbZn)3P208 
-h(PbZn) 
(OH2). 

Greasy. 

\.ed  to  brown 
and  black. 

)range  to  red 
and  gray. 

3-5 

kittle. 

5-9- 

6.2 

45 

Dufrenite  (37a). 

FeP04-h 

Silky,  weak. 

Green,  altering  to 

Green. 

3.5- 

kittle. 

.2- 

Fe(OH)2. 

yellow  and  brown. 

•4 

46 

Erythrite  (38). 

Co3As2O8 
+8H2O. 

Dearly  to 
adamantine. 

•led,  sometimes 
gray. 

Jaler  red. 

•5- 
•5 

Sectile. 

•95 

47 

Scorodite  (38). 

FeAsO4 

Vitreous. 

Green  to  brown. 

White. 

.5- 

kittle. 

.1- 

+2H2O. 

•3 

48 

Torbernite  (39). 

(CuU)3P208 

'early. 

jreen. 

5aler  green. 

_ 

^aminae 

•4- 

+8H2O. 

•5 

brittle. 

.6 

49 

Autunite  (39). 

(CaU)3P208 

Dearly. 

Yellow. 

3aler  yellow. 

,aminae 

- 

• 

-f8H2O. 

•5 

brittle. 

.2 

5° 

Sussexite  (40). 

H(Mn,Mg) 
B03. 

Silky  to 
pearly. 

White,  to  pinkish 
or  yellowish. 

White. 

rlexible. 

•4 

TABLE. 


93 


Form. 

Cleavage. 

Other 
Properties. 

Confirmatory  Chemical  Tests. 

Massive,  scaly  crystal- 
line or  earthy. 

Mone. 

Opaque. 

B.  B.  fuses  readily  to  a  yellowish  glass;    yields  metallic 
lead  with  soda  on  charcoal. 

I.  Octahedrons,  also  do- 
decahedrons and  cubes. 

Octahedral, 
indistinct. 

Translucent 
to  opaque. 

B.  B.  infusible;    zinc  oxide  coating  with  borax  and  soda 
on  charcoal. 

II.       Octahedrons,     also 
granular  massive. 

Basal,  nearly 
perfect. 

Opaque. 

B.  B.  infusible;    amethystine   bead   with   borax,   evolves 
chlorine  with  HC1. 

Pulverulent. 

Earthy. 

Opaque. 

B.  B.  on  charcoal  in  R.  F.  yields  globules  of  metallic  lead 

II.  Small  octahedrons. 

^one. 

Transparent 

B.  B.  infusible  ;  insoluble. 

to  opaque. 

Amorphous,  pisolitic  and 
clay-like. 

!^one. 

Opaque. 

B.  B.  infusible;   water  in  closed  tube;  blue  color  with  co- 
balt solution. 

I.  Capillary  crystals,  also 
botryoidal  and  earthy. 

Cubic  and 
pyramidal. 

Astringent 
taste. 

B.  B.  on  charcoal,  volatilizes,    forming  white   fumes   and 
coating;   white  sublimate  in  tubes. 

I  .  Octahedrons,  also  gran- 
ular and  in  crusts. 

Octahedral, 
in  traces. 

Transparent 
to  translucent. 

B.  B.  on  charcoal,  fuses  easily;   white  coating  and  subli- 
mate;  soluble  in  I1C1. 

IV.  Prismatic  crystals;  al- 
so lamellar,columnar,  etc. 

Prismatic, 
perfect. 

Translucent. 

B.  B.  on  charcoal,  fuses  easily;   white  coating  and  subli- 
mate;  soluble  in  HC1. 

Compact,  also  incrusting 
and  pulverulent. 

^one. 

Translucent 
to  opaque. 

B.  B.  fuses  with  difficulty;   white  coating  on  charcoal  and 
water  in  closed  tube. 

IV.Crystals,prismatic  and 
tabular. 

Fracture 
conchoidal. 

Opaque. 

B.  B.  infusible;   decrepitates;'  yellow  bead   with   borax; 
decomposed  by  H2SO4. 

II.  Prismatic  and  pyram- 
idal crystals,  like  zircon. 

Prismatic, 
perfect. 

Opaque. 

B.  B.  infusible;  insoluble;   bluish  green  flame  after  moist- 
ening with  I12SO4. 

IV.  Crystals  rare,  coarse, 
uneven;  usually  massive. 

Perfect. 

Pleochroic. 

B.  B.  fuses  (1.5);    purplish  red  flame  with  HjjSO^;   de- 
crepitates;  soluble  in  HC1. 

IV.  Crystals  striated   and 
highly  complex. 

Basal, 
perfect. 

Transparent. 

B.  B.  decrepitates  and  fuses  (3)  to  a  clouded   glass,    col- 
oring flame  deep  yellow. 

IV.  Short,  prismatic  crys- 
tals. 

Prismatic, 
interrupted. 

Translucent. 

B.  B.  phosphoresces;     fuses   with   difficulty;    blue    color 
with  cobalt  solution;   soluble. 

V.  Always  massive. 

Rectangu- 
lar. 

Opaque. 
Pleochroic. 

B.  B.  fuses  (1.5)  to  a  black  magnetic  globule;   reactions 
for  Fe,  Mn,  and  P;   evolves  HF  with  H2SO4. 

VI.  Large,  coarse  crystals, 
also  massive. 

Basal, 
perfect. 

Translucent. 

B.  B.  fuses  (2)  with  intumescence;    yellowish  red  flame; 
green  flame  with  H2SO.i;   water  in  tube. 

IV.  Prismatic,  acicular,al- 
so  globular,  fibrous,  etc. 

Fracture, 
conchoidal. 

Translucent 
to  opaque. 

B.  B.  fuses  (2)  ;   bluish  green  flame;  water  inclosed  tube  ; 
metallic  copper  with  soda  on  charcoal. 

IV.  Small,  prismatic  and 
drusy,  also  massive. 

None. 

Transparent 
to  opaque. 

B.  B.  fuses,  and  yields  metallic  lead  on  charcoal;   water 
in  closed  tube. 

II.  Crystals  rare;    small; 
usually  massive  or  fibrous. 

Indistinct. 

Opaque. 
Pleochroic. 

B.  B.  fuses  (1.5);   water   in    closed    tube;    reactions   for 
iron;   soluble  in  HC1. 

V.  Crystals  prismatic,  also 
globular,  or  incrusting. 

Pinacoidal, 
perfect. 

Transparent 
to  opaque. 

B.  B.  fuses  (2);   water  in  closed  tube;   rose-red  solution 
with  HC1. 

IV.    Pyramidal   crystals; 
also  earthy,  amorphous. 

Imperfect. 

Translucent. 

B.  B.  fuses  easily,  coloring  flame    blue;   water    in   closed 
tube;    soluble  in  HC1. 

II.  Small,  square,  tabular 
crystals,  often  very  thin. 

Basal, 
perfect. 

Transparent 
to  opaque. 

B.  B.  fuses  (2.5)  and  colors  flame  green;   water  in  closed 
tube;    copper  with  soda  on  charcoal.     . 

IV.  Small,  square,  tabular 
crystals;   also  foliated. 

Basal, 
perfect. 

Transparent 
to  translucent. 

B.  B.  fuses  (2.5)  ;   water  in  closed  tube. 

Fibrous  seams  or  veins. 

Fibrous. 

Translucent. 

B.  B.  fuses  (2);   intense  yellowish  green  flame;    water  in 
closed  tube;   reactions  for  Mn. 

94 


SUPPLEMENTARY 


No 

Species. 

Composition. 

Luster. 

Color 

Streak. 

H. 

Tenacity. 

G 

51 

Boracite  (40). 

Mg7Cl2B16 

Vitreous  to 

White  to  gray, 

White. 

7- 

Brittle. 

2.9- 

O30 

adamantine 

yellow,  green 

3- 

52 

Howlite  (40). 

H5Ca2B5Si 

Subvitreous 

White. 

White. 

3-5 

Earthy. 

2.6 

OH 

glimmering 

52 

Colemanite  (40) 

Ca2B6()n 

Vitreous  to 

Colorless  or  white 

White. 

4~ 

Brittle. 

2.4 

•4-5  H20 

adamantine 

4-5 

5-1 

Uraninite  (40). 

Complex 

Submetallic 

Gray,  green, 

Brownish 
black  to 

5-5 

Brittle. 

6.4- 

uranate 

to  greasy 

brown  to  black 

olive-green 

9-7 

55 

Gummite  (40). 

Complex 

Greasy. 

Orange  to 

Yellow. 

2-5- 

Brittle. 

3-9- 

uranate 

reddish  brown 

3- 

4-2 

5< 

Thenardite  (42) 

Na2SO4. 

Vitreous. 

White  to 

White. 

2-3- 

Brittle. 

2-7 

brownish 

57 

Glauberite  (42). 

Na2SO4 

Vitreous. 

Pale  yellow 

White. 

2-5- 

Brittle. 

2-7- 

+CaSO4 

or  gray 

3- 

2.85 

S« 

Brochantite 

CuSO4 

Vitreous. 

Emerald-  green, 

Paler  green. 

3-5- 

Brittle. 

3-9 

(42) 

+3Cu(OH)2 

blackish  green 

4- 

59 

Linarite  (42). 

(PbCu)2SO4 

Vitreous. 

Deep  azure  blue. 

Pale  blue. 

2.5 

Brittle. 

5-3" 

(OH)2 

5-45 

60 

Mirabilite  (43). 

Na2SO4-h 

Vitreous. 

White. 

White. 

1.5- 

Brittle. 

1.5 

ioH2O. 

2. 

61 

Epsomite  (43). 

MgS04-f 

Vitreous  to 

White. 

White. 

2- 

Brittle. 

1-75 

7H20. 

earthy. 

2-5 

02 

Melanterite  (44)  . 

FeS04+ 

Vitreous. 

Green  to  white. 

White. 

2. 

Brittle. 

1.9 

7H2O. 

63 

Chalcanthite 

CuS04+ 

Vitreous. 

Blue  to  greenish. 

W'hite. 

2-5 

Brittle. 

2.1- 

(44). 

5H20 

2-3 

64 

Alunogen  (44). 

A12(S04)34- 

Vitreous  to 

White. 

White. 

1.5- 

Brittle. 

1.6- 

i8H2O. 

silky. 

2. 

1.8 

65 

Alunite  (44). 

K2A16S4O22+ 

Vitreous  to 

White. 

White. 

3-5- 

kittle. 

2.6- 

611,0. 

pearly. 

2-7     \ 

66 

Aurichalcite 

(ZnCu)5CO3 

Pearly. 

Green  to  sky-blue. 

Greenish  or 

2. 

Brittle. 

3-55- 

(47)- 

30H2. 

bluish. 

67 

rlydrozincite 

ZnCo3+ 

Dull. 

White,  to  grayish 

White. 

2- 

kittle  to 

3-6- 

(47)- 

2Zn(OH2). 

or  yellowish. 

2-5 

earthy. 

3-8 

68 

Gay-Lussite 

CaCO3+Na2 

Vitreous. 

White. 

White. 

2-3. 

Very  brittle. 

•95 

(47). 

C08+5H2O. 

1  n 

69 

Trona  (47). 

Na2CO3;HNa 

Vitreous. 

Gray. 

White. 

2-5- 

kittle. 

2.1     ;.! 

C03+2H20. 

!'.D 

70 

Hydromagne- 

3MgCO3  Mg 

Vitreous  to 

White. 

White. 

3-5 

kittle. 

.15-  ,S 

site  (47). 

(OH)2,3'H20. 

silky. 

.2      .  So 

7i 

Zaratite  (47). 

NiCO3,2Ni 

Vitreous. 

imerald-green. 

^aler  green. 

3- 

kittle. 

2.6-    icr 

(OH),,4H20. 

•25 

2-7      'o 

72 

Bismutite  (47). 

BioO8+CO 

Vitreous  to 

Vhite  to  green. 

Vhite  to 

_ 

kittle  to 

6.9      icr 

+H2O. 

dull. 

greenish  gray. 

•5 

earthy. 

aor 

73 

Petalite  (473). 

LiAl(Si2O5)2. 

Vitreous. 

Colorless,  white, 

Vhite. 

6- 

Brittle. 

2.4-     i 

gray,  etc. 

•5 

2.45    ® 

74 

Andesite  (48). 

\Ta2CaAl2Si2 

Vitreous  to 

Vhite,  gray,  etc. 

White. 

-6. 

Brittle. 

2.7    :.( 

O<j.             pearly. 

tssi 

75 

Anorthite  (48). 

HaAl2Si2O.         Vitreous. 

White,  gray,  etc. 

White. 

- 

kittle. 

2-75     : 

•5 

PABLE. 


95 


Form. 

Cleavage. 

Properties. 

Confirmato       Chemical  Tests. 

.  Tetrahedral,  also  cubes 
>ctahedrons,  etc. 

Fracture 
conchoidal 

Translucent. 
.  Pyroelectric. 

B.  B.  fuses  (2)  with  intumescence,  coloring  flame  green; 
pink  color  with  cobalt  solution. 

V.  Small,  imbedded  nod 
lies. 

Fracture 
even 

Sub- 
translucen 

B.  B.  fuses  easily,  coloring  flame  green  ;  water  in  closed 
tube. 

7.  Short,  prismatic  crys- 
als,  also  massive. 

Pinacoidal, 
perfect 

Transparent 
to  translucen 

B.  B.  decrepitates,  exfoliates,  fuses  imperfectly,  coloring 
flame  yellowish  green;   water  in  closed  tube. 

.  Crystals  rare;     usually 
nassive  or  botryoidal. 

Fracture 
conchoida 

Opaque. 

B.  B.  infusible;   gives  coating  of  lead  oxide  with  soda  on 
charcoal. 

Vmorphous,     looks    like 
jum. 

None. 

Opaque. 

B.  B.  infusible;   much  water  in  closed  tube. 

V.    Pyramidal   crystals; 
Iso  tabular. 

Basal, 

distinct 

Transparent 
to  transluceni 

B.  B.  fuses  easily,  coloring  flame  deep  yellow;   soluble  in 
water. 

T.  Tabular  crystals. 

Basal, 
perfect 

Transparent 
to  translucent 

B.  B.  decrepitates  and  fuses  (1.5),  coloring  flame  intensely 
yellow;   soluble  in  HC1. 

V.  Prismatic  or  acicular 
Iso  massive. 

Pinacoidal, 
perfect 

Transparent 
to  translucent 

B.  B.  fuses;   yields  metallic  copper  on  charcoal;   water  in 
closed  tube. 

T.  Prismatic    or    tabula 
rystals. 

Pinacoidal, 
perfect 

Translucent. 

B.  B.  fuses  easily,  yielding  metallic  copper  in  R.  F.;  water 
in  closed  tube. 

T.  Usually  in  efflorescen 

Pinacoidal, 

Transp.  etc. 

B.  B.  fuses  easily,  giving  an  intense  yellow    color  to    the 

rusts. 

perfect 

Saline  taste. 

flame;   water  in  closed  tube;   soluble  in  water. 

V.  Prismatic  also  botry- 
idal  and  iibrous. 

Pinacoidal, 
perfect 

Translucent. 
Bitter,  saline. 

3.  B.  fuses  in  water  of  crystallization  to  an  infusible  mass; 
water  in  tube;   soluble  in  water  ;  pink  color  with  Co.  sol. 

r.  Usually  fibrous  or  stal- 
ctitic,  also  massive. 

Basal, 
perfect. 

Translucent. 
Astringent. 

B.  B.  becomes  red,  then  black  and  magnetic;   very  solu- 
ble in  water;   yields  water  in  closed  tube. 

'.Also   massive,    stalac- 

Fracture 

Translucent. 

J.  B.  yields  copper   with    soda   on   charcoal;     water   in 

tic,  etc. 

conchoidal. 

Taste  metallic. 

closed  tube;   soluble  in  water. 

".  Usually  fibrous  masses 

Fibrous. 

Translucent. 

5.  B.  water  in  closed  tube;    blue  color  with  cobalt  solu- 

r cruots. 

Alum  taste. 

tion;   soluble  in  water. 

[I.  Rhombohedral,  also 
lassive  or  fibrous. 

Basal, 
distinct. 

Transparent 
to  opaque. 

1.  B.  decrepitates;  infusible;   water  in  closed  tube;  blue 
color  with  cobalt  solution. 

.  Acicular,  also  colum- 
ar,  plumose,  granular. 

None. 

Translucent. 

B.  B.  infusible;   blackens  and  colors  flame  deep  green; 
yields  water;   effervesces  in  HC1. 

(assive,  fibrous,  earthy, 
nnpact,  pisolitic,  etc. 

iarthy. 

Opaque. 

B.  B.  infusible;   water   in    closed  tube  ;  effervesces   with 
HC1. 

.  Elongated    and    flat- 
ned  crystals. 

3rismatic, 
perfect. 

"ranslucent. 

B.  B.  fuses  easily,  coloring  flame  intensely  yellow;    effer- 
vesces in  HC1. 

.  Crystals,  also  often  fi- 
rous  or  columnar. 

Jmacoidal, 
perfect. 

"ranslucent. 

.  B.  fusible,    coloring   flame   intensely   yellow;     yields 
water;   effervesces. 

.  Small,  acicular  crystals, 
so  amorphous. 

^one. 

"ranslucent 
to  opaque. 

.  B.  infusible;   water  in  closed  tube;   effervesces  in   hot 
HC1. 

icrus'iing;   also  massive 
•  compact. 

None. 

Vansparent 
o  translucent. 

.  B.  infusible;   water  in  closed  tube;    effervesces  readilv 
in  HC1. 

icrusting     or      earthy; 
norphous. 

Earthy. 

Opaque. 

5.  B.  decrepitates,  fuses  readily;   yellow  coating  on  char- 
coal;  water  in  tube. 

.  Crystals  rare,   usually 
assive  or  foliated. 

Basal, 
perfect. 

Vansparent 
o  translucent. 

.  B.  infusible;   purplish  red  flame  (lithia);   insoluble. 

[.Crystals  rare;  usually 
assive. 

?asal  and 
-•in.  perfect. 

Dpaque. 

.  B.  fuses  in  thin  splinters. 

[.  Usually  massive. 

iasal  and 

"ranslucent. 

.  B.  fuses  at  5  to  a  colorless  glass;   usually  insoluble. 

)in.  perfect. 

96 


SUPPLEMENTAL; 


! 


No. 

Species. 

Composition. 

Luster. 

Color 

Streak. 

H. 

Tenacity. 

G. 

76 

Microcline  (48). 

KAlSi308. 

Vitreous. 

White,  red,  green. 

White. 

6- 
6-5 

Brittle.  . 

2-55 

77 

Acmite  (50). 

NaFeSi2O6. 

Vitreous. 

Brownish,  reddish 

Pale  yellowish 

6- 

Brittle. 

3f 
•  J 

brown,  green. 

gray 

6.5 

3-55 

78 

Babingtonite 

(CaFeMn) 

Vitreous. 

Dark  greenish 

Greenish  gray 

5-5- 

Brittle. 

3-35 

(50). 

SiO3. 

black 

6. 

79 

Anthophyllite 

(MgFe)Si03. 

Vitreous. 

Brown  to  gray 

White  to  gray 

5-5- 

Brittle  to 

3-i- 

(50- 

and  green 

6. 

flexible 

3-2 

80;  Glaucophane 

NaAlSi2O6+ 

Vitreous  to 

Blue  to  black 

Grayish  blue. 

6- 

Brittle. 

3-i 

(50- 

(MgFe)SiO3. 

pearly. 

and  gray 

6.5 

Si 

Crocidolite  (51). 

NaFeSi2O64- 

Silky  to 

Lavender-blue 

Like  color. 

4- 

Flexible  to 

3-2- 

FeSi03. 

dull. 

or  leek-green 

brittle 

3-3 

82 

Arfvedsonite 

(NaCaFeAl) 

Vitreous. 

Pure  black  and 

Bluish  gray. 

6. 

Brittle. 

3-45 

(50- 

Si03. 

deep  green 

83 

lolite  (52a). 

(HMgFeAl) 

Vitreous. 

Light,  dark  and 

Gray. 

7- 

Brittle. 

2.6- 

SiO3. 

smoky  blue 

7-5 

2.65 

84 

Cancrinite  (53). 

(HNaCaAl)2 

Vitreous  to 

White,  yellow, 

White. 

5-6- 

Brittle. 

2.4- 

SiO4. 

greasy. 

green,  blue,  etc 

2-5 

85 

Phenacite  (57). 

Be2SiO4. 

Vitreous. 

Colorless  to  red, 

White. 

7-5- 

Brittle. 

3. 

yellow,  brown 

8. 

86 

Danburite  (60). 

CaB2Si2O8i 

Vitreous  to 

Colorless  to  wine, 

White. 

7- 

Brittle. 

3- 

greasy. 

yellow  and  brown 

7-25 

Sy'Gadolinite   (61). 

Be2FeY2Si2 

Vitreous  to 

Black,  greenish 

Greenish  gray. 

6-5- 

Brittle. 

4- 

Oio- 

greasy. 

black  to  brown 

7- 

4-5 

88 

Axinite  (63). 

Complex 

Vitreous, 

Brown,  blue, 

White. 

6-5- 

Brittle. 

3-3 

silicate. 

eminent. 

gray,  yellow,  etc. 

7- 

89 

Ilvaite  (65). 

HCaFe3Si2O9. 

Submetallic. 

Iron-  black. 

Black. 

5-5- 

Brittle. 

4- 

6. 

4-05 

90 

Harmotome 

H2(K2Ba)Al3 

Vitreous. 

White  to  red, 

White. 

4-5 

Brittle. 

2-44- 

(7»)jSi«016-f4HsO 

yellow,  brown. 

2-5 

9i 

Scolecite  (73). 

CaAl2Si3Oio+ 

Vitreous  or 

White. 

White. 

5~ 

Brittle. 

2-15- 

3H20. 

silky. 

5-5 

2.4 

92 

Mesolite  (73). 

Near  scolecite. 

Vitreous  or 

White,  to 

White. 

5- 

Brittle. 

2.2- 

silky. 

yellowish. 

2.4 

93 

Corundophilite 

MguAl8Si6O35 

Pearly. 

Green. 

White. 

2-5 

Flexible, 

2.9 

(77)- 

+  ioH2O. 

sectile. 

94  Stilpnomelane 

Complex 

Pearly  to 

Black  to  orange. 

liray. 

3-4 

flexible. 

2.8- 

(77)- 

silicate. 

submetallic. 

95  Jefferisite  (75). 

A  hydrated 

Pearly. 

Yellowish  brown. 

White. 

!'5 

^lexible, 

2-3 

mica. 

sectile. 

96 

Allophane  (79). 

Al2SiO5+ 

Vitreous  to 

Pale  sky-blue  to 

White. 

3* 

Very  brittle. 

.85- 

5H20. 

waxy. 

colorless. 

9 

97 

Chloropal  (80). 

HeFe2Si3O12 

Dull  or 

Greenish  yellow 

Like  color. 

2-5- 

Brittle  to 

•7- 

+2HaO. 

opaline. 

to  green. 

4-5 

earthy. 

2.1 

98 

Dysanalyte(82). 

Titano-niobate 

Submetallic. 

[ron-black. 

Grayish. 

5-6. 

Brittle. 

4-13 

of  Ca.Fe. 

99 

Ozocerite  (83).     Hydrocarbon. 

Waxy. 

White  to  yellow 

Like  color. 

Very 

Waxy. 

D.85- 

and  dark  brown. 

soft. 

D.90 

100 

Albertite  (84). 

Hydrocarbon. 

Pitch-like, 

Jet-black. 

Like  color. 

-2. 

Brittle. 

•I 

brilliant. 

TABLE. 


97 


Form. 

Cleavage. 

Other 
Properties. 

Confirmatory  Chemical  Tests. 

VI.  Crystals   like    ortho- 
clase;   also  massive. 

Sasal  and 
)in.  perfect. 

"ransparent 
o  translucent. 

B.  B.  fuses  at  5  ;   not  affected  by  acids. 

V.  Striated,prismatic  crys- 
tals, acutely  terminated. 

Msmatic, 
distinct. 

Opaque, 
'leochroic. 

B.  B.  fuses  at  2  to  a  lustrous  black  magnetic  globule. 

VI.  Small   crystals,   like 
hornblende. 

'rismatic, 
perfect. 

Opaque. 
Jleochroic. 

5.  B.  fuses  at  2.7  to  a  black,  magnetic  globule;    not  af- 
fected by  acids. 

IV.  Prismatic  habit,  usu- 
ally lamellar  or  tibrous. 

Msmatic, 
perfect. 

'ransparent 
to  opaque. 

S.  B.  fuses  with  difficulty  to  a  black  magnetic  enamel; 
not  affected  by  acids. 

V.  Thin,   prismatic    crys- 
tals, columnar,  fibrous. 

3rismatic, 
perfect. 

>anslucent. 
Heochroic. 

Fibrous,asbestus-like,also 
massive. 

3nsmatic, 
perfect. 

Opaque, 
'leochroic. 

5.  B.  colors  flame  yellow  and  fuses  easily  with  intumes- 
cence to  a  black  magnetic  mass. 

V.  Slender  prisms,  often 
tabular. 

Prismatic, 
perfect. 

Opaque, 
3leochroic. 

5.  B.  colors  flame  yellow  and  fuses  at  2  with  intumescence 
to  a  black  magnetic  mass. 

IV.  Twin    crystals,    also 
massive,  compact. 

Dinacoidal, 
distinct. 

"ranslucent. 
3leochroic. 

5.  B.  infusible;   partially  decomposed  by  acids. 

III.     Prismatic     crystals 
rare,  usually  massive. 

Msmatic, 
perfect. 

"ransparent 
o  translucent. 

}.  B.  fuses  (2)  with  intumescence;   water  in  closed  tube> 
effervesces  and  gelatinizes  with  HC1. 

III.  Rhombohedral,  short 
crystals. 

Msmatic, 
distinct. 

Transparent 
to  opaque. 

5.  B.  infusible;   dull  blue  with  cobalt  solution. 

IV.  Prismatic  crystals. 

"racture 
uneven. 

Vansparent 
o  translucent. 

3.  B.  fuses    (3.5)  to   a   colorless   glass,    coloring   O.  F. 
green. 

V.  Crystals   rough,   pris- 
matic, also  massive. 

rracture 
conchoidal. 

Translucent. 
Jleochroic. 

3.  B.  infusible,  but  swells  up  and  often  glows;  gelatinizes 
with  HC1. 

VI.   Crystals   broad   anc 
sharp-edged;   massive. 

distinct. 
Conchoidal. 

Dleochroic. 
3yroelectric. 

B.  B.  fuses  readily  with  intumescence  to  a  greenish  black 
glass;   insoluble. 

IV.    Prismatic,    striated, 
columnar,  or  compact. 

Distinct, 
iven. 

Opaque. 

B.  B.  fuses  quietly  at  2.5  to  a  black,  magnetic  bead;   gel- 
atinizes with  HC1. 

V.    Cruciform,    penetra- 
tion twin  crystals. 

Pinacoidal 
and  basal 

Translucent. 

B.  B.  whitens  and  fuses  at  3.5;  decomposed  by  HC1  with- 
out gelatinizing;   water  in  tube. 

V.   Acicular    to    fibrous 
divergent  or  radiate. 

Prismatic, 
perfect 

Transp.  etc. 
Pyroelectric. 

B.  B.  intumesces  and  fuses  at  2;   gelatinizes   with    HC1; 
water  in  tube. 

V.  and  VI.   Acicular   to 
fibrous,  radiate. 

Prismatic, 
perfect 

Transparent 
to  opaque 

B.  B.  intumesces  and  fuses  easily;   gelatinizes  with  HC1; 
water  in  closed  tube. 

V.  Micaceous,   six-sided 

tabular  crystals. 

Basal, 
eminent 

Transparent 
•to  opaque 

B.  B.  infusible;   water  in  closed  tube. 

Foliated  plates  or  velvety 
coatings. 

Perfect. 

Translucent. 

B.  B.  fuses  easily  to  a  black,  shining,  magnetic  globule; 
much  water  in  tube. 

Micaceous,    broad,   crys 
talline  plates. 

Basal, 
perfect 

Translucent. 

B.  B.  intumesces  remarkably  and  fuses;   water  in  closed 
tube. 

Amorphous,     incrustinj 
mammillary. 

Conchoidal, 
to  earthy 

Translucent. 

B.  B.  crumbles  but  is  infusible;  blue  with  cobalt  solution; 
yields  water;   gelatinizes  with  HC1. 

Compact,      massive      o 
earthy. 

Conchoidal, 
to  earthy 

Opaque. 
Meagre  feel. 

B.  B.  infusible;   becomes  black  and  magnetic;   water  in 
closed  tube. 

I.  Cubic  crystals. 

Cubic. 

Opaque. 

B.  B.  infusible;   decomposed  by  H2SO4. 

Amorphous. 

None. 

Translucent. 
Greasy  feel. 

B.  B.  fuses  and  burns. 

Amorphous,  like  asphalt 

Fracture 
conchoida 

Opaque. 

B.  B.  fuses  and  burns. 

SYNOPSIS  OF  THE  CLASSIFICATION  OF  MINERALS. 

SUBKINGDOM    OF    ELEMENTS. 

Class  of  Metals. 

1.  Gold  Group. — Gold,  silver. 

2.  Iron   Group. — Copper,  iron,    mercury,    platinum,    iridos- 

mine. 

Class  of  Metalloids. 

3.  Arsenic  Group. — Bismuth,  antimony,  arsenic,    tellurium. 
\.     Sulphur  Group. — Sulphur. 

5.  Carbon-Silicon   Group. — Diamond,  graphite. 

SUBKINGDOM  OF  BINARY  COMPOUNDS. 
Class  of  Sulphides,  Sulpharsenides,  Arsenides,  etc. 

GOLD,    IRON   AND   TIN   SUBCLASS. 

Proto  or  Galena   Group. 

6.  Galena   Family. — Galenite,    bornite,    argentite,    hessite, 

petzite,  altaite. 

7.  Chalcocite  Family. — Chalcocite,  stromeyerite. 

8.  Blende  Family. — Sphalerite,  alabandite,  pentlandite,  met- 

acinnabarite,  tiemannite. 

9.  Pyrrhotite  Family. — Cinnabar,  millerite,    pyrrhotite,  nic- 

colite,  polydymite,  covellite,  greenockite. 
Deuto  or  Pyrite  Group. 

10.  Pyrite  Family. — Pyrite,    chalcopyrite,   smaltite,   cobalt- 

ite,  linnseite,  sperrylite,  stannite,  gersdorffite. 

11.  Marcasite  Family. — Marcasite,  arsenopyrite,  lollingite. 

12.  Sylvanite  Family. — Sylyanite,  nagyagite. 

ARSENIC   AND   SULPHUR   SUBCLASS. 

13.  Realgar  Family. — Realgar. 

14.  Orpiment    Family. — Orpiment,    stibnite>     bismuthinite, 

tetradymite,  kermesite. 

15.  Molybdenite  Family. — Molybdenite. 

SULPHARSENITES,    SULPHANTIMONITES,    ETC. 

1 6.  Stephanite,  tetrahedrite,  pyrargyrite,  proustite,  enargite, 

bournonite,  zinkenite,  berthierite,  cosalite,  jamesonite, 
boulangerite,  polybasite. 

Class  of  Chlorides,  Bromides,  Iodides,  and  Fluorides. 

GOLD,    IRON   AND   TIN    SUBCLASS. 

Anhydrous  Division. 

17.  Halite   Family.—^ Halite,    sylvite,    cerargyrite,    embolite, 

bromyrite,  iodyrite. 

1 8.  Fluorite  Family. — Fluorite,  cryolite. 
Oxy  chloride  Division. 

19.  Atacamite  Family. — Atacamite. 


99 
Class  of  Oxides. 

GOLD,    IRON   AND   TIN    SUBCLASS. 

Anhydrous  Division. 
Protoxide   Group. 

20.  Cuprite  Family. — Cuprite. 

21.  Zincite  Family. — Water,  zincite,  massicot. 

22.  Melaconite  Family. — Melaconite. 
Protoxide  and  Sesquioxide   Group. 

23.  Spinel  Family. — Spinel,  magnetite,  franklinite,  chromite, 

gahnite,  hausmannite,  braunite,  minium, 

24.  Chrysoberyl  Family. — Chrysoberyl. 
Sesquioxide   Group. 

25.  Corundum  Family. — Corundum,  hematite,  menaccanite. 
Deutoxide  Group. 

26.  Rutile  Family. — Cassiterite,  rutile,  zircon,  polianite. 

27.  Brookite  Family. — Brookite,  pyrolusite,  octahedrite. 
Hydrous  Division. 

28.  Turgite  Family. — Turgite. 

29.  Diaspore  Family. — Diaspore,  gothite,  manganite. 

30.  Limonite  Family. — Limonite,  bauxite. 

31.  Brucite  Family. — Brucite,  gibbsite. 

32.  Psilomelane  Family. — Psilomelane,  wad. 

ARSENIC   AND   SULPHUR   SUBCLASS. 

32a.  Arsenolite,  senarmontite,  valentinite,  stibiconite. 

CARBON- SILICON   SUBCLASS. 

33.  Anhydrous  Division. — Quartz. 

34.  Hydrous  Division. — Opal. 

SUBKINGDOM    OF   TERNARY    COMPOUNDS. 

Class  of  Tantalates  and  Columbates. 

35.  Columbite  Family. — Columbite-tantalite,  samarskite, 

polycrase. 

Class  of  Phosphates,  Arsenates,  etc.  t 

Anhydrous  Division. 

36.  Monazite  Family. — Monazite. 

37.  Apatite  Family. — Apatite,  pyromorphite,  mimetite,  van 

adinite. 
37a.  Xenotime,  triphylite,  beryllonite,  herderite,  triplite,  am 

blygonite,  olivenite,  descloizite,  dufrenite. 
Hydrous  Division. 

38.  Vivianite  Family. — Vivianite,  erythrite,  scorodite. 

39.  Wavellite  Family. — Wavellite,    lazulite,  turquois,  autun 

ite,  torbernite. 


100 

Class  of  Berates  and  Uranates. 

40.  Borax,  ulexite,  sussexite,  boracite,  howlite,   colemanite, 

uraninite,  gummite. 

Class  of  Tungstates  and  Molybdates. 

41.  Wolframite,  wulfenite,  scheelite. 

Class  of  Sulphates,  Chromates,  etc. 

Anhydrous  Division. 

42.  Barite  Family. — Barite,  celestite,  anhydrite,  anglesite. — 

Thenardite,    glauberite. — Brochantite, 
linarite. 
Hydrous  Division. 

43.  Gypsum     Family. — Gypsum,      mirabilite. — Epsomite. — 

Melanterite,  chalcanthite. 

44.  Alum  -Family. — Kalinite,  alunogen. — Alunite. 

Class  of  Carbonates. 

Anhydrous  Division. 

45.  Calcite  Family. — Calcite,  dolomite,  magnesite,  siderite, 

rhodochrosite,  smithsonite. 

46.  Aragonite    Family.— Aragonite,    witherite,    strontianite, 

cerussite. 
Hydrotts  Division. 

47.  Malachite     Family. — Malachite,     azurite,     aurichalcite, 

hydrozincite,  gay-lussite,    trona,  hydro- 
magnesite,  zaratite,  bismutite. 
Class  of  Silicates. 

Anhydrous  Division, 
Poly  silicate  Group. 

4ya.  Petalite  Family. — Petalite. 

48.  Feldspar  Family. — Orthoclase,  microcline,  albite,  oligo- 

clase,  andesite,  labradorite,  obsidian. 
Metasilicate   Group. 

49.  Leucite  Family. — Leucite. 

50.  Pyroxene  Family. — Enstatite,     hypersthene,     pyroxene, 

spodumene,  jadeite,  wollastonite, 
pectolite,  rhodonite,  acmite,  bab- 
ingtonite. 

51.  Amphibole  Family. — Amphiboie,    anthophyllite,    crocid- 

olite,   arfvedsonite,    glaucophane. 

52.  Beryl  Family. — Beryl. 
52a.  lolite  Family. — lolite. 

Orthosilicate  Group. 

53.  Nephelite  Family. — Nephelite,  cancrinite. 

54.  Sodalite  Family. — Sodalite,  haiiynite,  lazurite. 

55.  Garnet  Family. — Garnet. 


'    '  i V  ''  V          J,  i  *'     101 

56.  Chrysolite  Family. — Chrysolite,  tjephpoite..,  j*>5»'*"  j  / 

5  7 .  Phenacite  Family. — Willeinite/  pheniaiitCy '  diOpta^e. " ' 

58.  Scapolite  Family. — Wernerite. 

59.  Vesuvianite  Family. — Vesuvianite. 

60.  Topaz  Family. — Danburite,    topaz,    andalusite,  silliman- 

ite,  cyanite. 

61.  Datolite  Family — Datolite,  gadolinite. 

62.  Epidote  Family. — Zoisite,  epidote,  allanite 

63.  Axinite  Family. — Axinite. 

64.  Prehnite  Family. — Prehnite. 
Sub  silicate  Group. 

65.  Humite  Family. — Chondrodite,  ilvaite. 

66.  Tourmaline  Family. — Calamine,  tourmaline. 

67.  Staurolite  Family. — Staurolite. 
Anhydrous  Division. 

Zeolite  Group. 

68.  Apophyllite  Family. — Apophyllite. 

69.  Heulandite  Family. — Heulandite. 

70.  Phillipsite  Family. — Stilbite,  laumontite,  harmotome. 

71.  Chabazite  Family. — Chabazite,  gmelinite. 

72.  Analcite   Family. — Analcite. 

73.  Natrolite  Family. — Natrolite,  mesolite,  scolecite. 

74.  Thomsonite  Family. — Thomsonite. 
Mica   Group. 

75.  Mica  Family. — Muscovite,    biotite,   phlogopite,    lepido- 

lite,  lepidomelane,  pinite,  jefferisite. 

76.  Margarite  Family. — Margarita,  seybertite,  chloritoid. 

77.  Chlorite  Family. — Clinochlore,  prochlorite,  corundophi- 

lite,  stilpnomelane. 

78.  Serpentine  Family. — Serpentine,     devveylite,    garnierite, 

talc,  sepiolite,  glauconite. 

79.  Kaolin  Family. — Kaolinite,  halloysite,  montmorillonite, 

pyrophyllite,  allophane. 

80.  Chrysocolla  Family. — Chrysocolla,  chloropal. 

Class  of  Titano-silicates  and  Titanates. 

81.  Titanite  Family. — Titanite. 

82.  Perovskite  Family. — Dysanalite. 

Class  of  Hydrocarbons. 

83.  Simple  Hydrocarbons. — Petroleum,  ozocerite. 

84.  Oxygenated  Hydrocarbons. — Amber,    copal,    asphaltum, 

albertite,  coal,  etc. 


Synopsis  of  the  Classification  of  Minerals  by  the  Basic  Elements 

'*  (Exclusive' o*f  the  SiKcaVes 7, — the  so-called  Economic  Classification. 
The  names  of  the  species  useful  as  ores  are  printed  in  italics. 

Gold  Group. —  Gold,  pyrite  {auriferous},  petzite,  sylvanite,  nagyagite. 

Silver  Group. — Silver,  argentite,  galenite  {argentiferous),  hessite,  stromeyerite, 
stephanite,  tetrahedrite,  pyrargyrite,  proustite,  polybasite,  cerargyrite,  embo- 
lite,  bromyrite,  iodyrite. 

Platinum  Group. — Platinum,  iridosmine,  sperrylite. 

Mercury  Group. — Mercury,  metacinnabarite,  tiemannite,  cinnabar. 

Copper  Group. — Copper,  bornite,  chalcocite,  stromeyeiite,  covellite,  chalcopyrite, 
tetrahedrite,  enargite,  bournonite,  atacamite,  cuprite,  melaconite,  olivenite, 
torbernite,  brochantite,  linarite,  chalcanthite,  malachite,  azurite,  aurichalcite. 
(Also,  chrysocolla.~) 

Lead  Group. —  Galenite,  altaite,  bournonite,  zinkenite,  cosalite,  jamesonite,  boulan- 
gerite,  massicot,  minium,  pyromorphite,  mimetite,  vanadinite,  descloizite,  wulf- 
enite,  anglesite,  linarite,  cerussite. 

Zinc  Group. — Sphalerite,  zincite,  franklinite,  gahnite,  smithsonite,  aurichalcite, 
hydrozincite.  (Also,  willemite,  calamine.} 

Cadmium  Group. —  Greenockite,  sphalerite  (cadmiferous^) 

Tin  Group. — Stanmte,  cassiterite. 

Titanium  Group. — Menaccanite,  rutile,  octahedrite,  brookite,  polycrase. — Zircon. 

Cobalt  and  Nickel  Group. — Pentlandite,  millerite,  pyrrhotite  (nickeliferous},  nic- 
colite,  polydymite,  smaltite,  cobaltite,  linntette,  gersdorffite,  erythrite,  zaratite. 
(Also,  garnierite^) 

Uranium  Group. — Samarskite,  autunite,  torbernite,  uraninite,  gummite. 

Iron  Group. — Iron,  bornite,  pentlandite,  pyrrhotite,  polydymite,  pyrite,  chalcopy- 
rite, smaltite,  marcasite,  arsenopyrite,  lollingite,  berthierite,  magnetite,  frank- 
linite, chromite,  hematite,  menaccanite,  turgite,  gothite,  limonite,  columbite- 
tantalite,  samarskite,  triphylite,  tnplite,  dufrenite,  vivianite,  scorodite,  wolfram- 
ite, melanterite,  siderite,  ankerite. 

Manganese  Group. — Alabandite,  franklinite,  hausmannite,  braunite,  polianite,  py- 
rolusite,  manganite,  psilomelane,  wad,  columbite-tantalite,  triplite,  sussexite, 
wolframite,  rhodochrosite. 

Aluminum    Group. —  Cryolite,    spinel,    gahnite,    chrysoberyl,    corundum,    diaspore, 
.     bauxite,  gibbsite,  amblygonite,  wavellite,  lazulite,   turquois,  kalinite,    alunogen, 
alunite. 

Beryllium  Group. — Chrysoberyl,  beryllonite,  herderite. 

Cerium,  etc.,  Group. — Samarskite,  polycrase,  xenotime,  monazite. 

Magnesium  Group. — Spinel,  brucite,  boracite,    sussexite,   epsomite,    dolomite,   mag- 

nesite,  hydromagnesite. 
Calcium  Group. — Fluorite,  apatite,  herderite,  autunite,  ulexite,    howlite,  colemanite, 

scheelite,    anhydrite,    glauberite,    gypsum,    calcite,    dolomite,    aragonite,   gay- 

lussite. 

Barium  and  Strontium  Group. — Barite,  celestite,  witherite,  strontianite. 
Potassium  and  Sodium  Group. —  Halite,    sylvite,    cryolite,    beryllonite,    amblygonite, 

borax,  ulexite,    thenardite,    glauberite,   mirabilite,    kalinite,   alunite,   gay-lussite, 

trona. 

Lithium  Group. — Triphylite,  amblygonite. 
Hydrogen  Group. — Water. 

Arsenic  Group. — Arsenic,  realgar,  orpiment,  arsenolite.     (Also,  arsenopyrite,  smal- 
tite, cobaltite,  etc.) 
Antimony  Group. — Antimony,    stibnite,    kermesite,    senarmontite,    valentinite,   stibi- 

conite. 

Bismuth  Group. — Bismuth,  bismuthinite,  tetradymite,  bismutite. 
Tellurium  Group. — Tellurium,  molybdenite. 
Sulphur  Group. —  Sulphur.     (Also,  pyrite,  marcasite,  etc.) 
Silicon  Group. — Quartz,  opal. 
Carbon  Group. — Graphite,  diamond. 


INDEX. 


Acadialite,  v.  Chabazite. 

Acmite,  96. 

Actinolite,  72,  80. 

Agate,  84. 

Alabandite,  36. 

Alabaster,  v.  Gypsum. 

Albertite,  96. 

Albite,  84. 

Allanite,  36,  40,  74,  82. 

Allophane,  96. 

Almandite,  v.  Garnet. 

Altaite,  90. 

Alum,  v.  Kalinite, 

Alunite,  94. 

Alunogen,  94. 

Amber,  64. 

Amblygonite,  92. 

Amethyst,  84,  88. 

Amphibole,  60,  62,  72,  76,  80,  86. 

Analcite,  78. 

Andalusite,  86,  88. 

Andesite,  94. 

Anglesite,  66. 

Anhydrite,  70. 

Ankerite,  68. 

Anorthite,  94. 

Anthophyllite,  96. 

Anthracite,  v.  Mineral  Coal. 

Antimony,  42,  48. 

Apatite,  76. 

Apophyllite,  78. 

Aquamarine,  v.  Beryl. 

Aragonite,  68. 

Arfvedsonite,  96. 

Argentite,  32,  34,  40,  42. 

Arsenic,  36,  42,  48. 

Arsenolite,  92. 

Arsenopyrite,  30,  32,  44,  46,  48. 

Asbestus,  62,  72. 

Asphaltum,  50,  58. 

Atacamite,  60. 

Augite,  60,  86. 

Aurichalcite,  94. 

Autunite,  92. 

Axinite,  96. 

Azurite,  60. 


Babingtonite,  96. 

Barite,  68. 

Bauxite,  92. 

Berthierite,  90. 

Beryl,  88. 

Beryllonite,  92. 

Biotite,  32,  34,  62,  66. 

Bismuth,  40,  42,  46,  48. 

Bismuthinite,  40. 

Bismutite,  94. 

Blue  vitriol,  z>.  Chalcanthite. 

Boracite,  94. 

Borax,  62. 

Bornite,  28. 

Boulangerite,  90. 

Bournonite,  34,  42. 

Brittle  silver  ore,  v.  Stephanite. 

Brochantite,  94. 

Bromyrite,  90. 

Brookite,  36,  40,  74,  82. 

Brucite,  64,  70. 

Calamine,  68,  70,  76. 

Calcite,  64,  68. 

Calc  spar,  v.  Calcite. 

Cancrinite,  96. 

Capillary  pyrites,  v.  Millerite. 

Carnelian,  84. 

Cassiterite,  28,  38,  54,  82,  88. 

Celestite,  68. 

Cerargyrite,  64. 

Cerussite,  66. 

Chabazite,  78. 

Chalcanthite,  94. 

Chalcedony,  84. 

Chalcocite,  34,  42. 

Chalcodite,  v.  Stilpnomelane. 

Chalcopyrite,  30,  32. 

Chalk,  64. 

Chert,  84. 

Chiastolite,  v.  Andalusite. 

Chlorite,  v.  Prochlorite. 

Chloritoid,  72,  80. 

Chloropal,  96. 

Chondrodite,  76,  84. 

Chromite,  36,  40,  54,  74. 

Chromic  iron,  v.  Chromite. 


104 


Chrysoberyl,  88. 

Chrysocoila,  62,  66. 

Chrysolite,  86,  88. 

Chrysoprase,  84. 

Chrysotile,  70,  72. 

Cinnabar,  26,  28,  50,  52,  54. 

Cinnamon  stone,  v.  Garnet. 

Clay,  v.  Kaolinite. 

Clinochlore,  60,  62,  66. 

Cobaltite,  44,  46,  48. 

Columbite-tantalite,  38,  52,  54,  58. 

Colemanite,  94. 

Copalite,  64. 

Copper,  26. 

Copperas,  v.  Melanterite, 

Copper  glance,  v.  Chalcocite. 

Copper  pyrites,  v.  Chalcopyrite. 

Corundophilite,  96. 

Corundum,  82,  88. 

Cosalite,  90. 

Covellite,  90. 

Crocidolite,  96. 

Cryolite,  70. 

Cuprite,  26,  28,  52,  54. 

Cyanite,  72,  80,  88. 

Danburite,  96. 
Datolite,  76. 
Descloizite,  92. 
Deweylite,  64,  70. 
Diamond,  88. 
Diaspore,  80,  82,  86. 
Dioptase,  60. 
Dolomite,  68,  76. 
Dufrenite,  92. 
Dysanalyte,  96. 

Elaeolite,  v.  Nephelite. 
Embolite,  90. 
Emerald,  v.  Beryl. 
Emerald  nickel,  v.  Zaratite. 
Emery,  38,  46. 
Enargite,  34. 
Enstatite,  76. 
Epidote,  76,  80,  82,  86. 
Epsomite,  94. 
Epsom  salt,  v.  Epsomite. 
Erythrite,  92. 
Essonite,  v.  Garnet. 

Feldspar,  84. 

Felsite,  84. 

Fibrolite,  v.  Sillimanite. 


Flint,  84. 
Fluorite,  70,  76. 
Fluor  spar,  v.  Fluorite. 
Franklinite,  38. 
Freieslebenite,  90. 

Gadolinite,  96. 

Gahnite,  92. 

Galena,  v.  Galenite. 

Galenite,  42. 

Garnet,  82,  86,  88. 

Garnierite,  62. 

Gay-Lussite,  94. 

Gersdorffite,  90. 

Geyserite,  64. 

Gibbsite,  70. 

Glauberite,  94. 

Glauber  salt,  v.  Glauberite. 

Glauconite,  60. 

Glaucophane,  96. 

Gmelinite,  78. 

Gold,  30. 

Gothite,  28,  36,  38,  52,  56. 

Graphite,  32,  40. 

Gray  Copper,  v.  Tetrahedrite. 

Greenockite,  90. 

Grossularite,  v.  Garnet. 

Gum  mite,  94. 

Gypsum,  62,  64. 

Halite,  62,  66. 

Halloysite,  64. 

Harmotome,  96. 

Hausmannite,  92. 

Heavy  spar,  v.  Barite. 

Hematite,  28,  34,  36,  38,44,  46,  52,  54. 

Herderite,  92. 

Hessite,  90. 

Heulandite,  70,  78. 

Hornblende,  60,  72,  80,  86. 

Horn  silver,  v.  Cerargyrite. 

Howlite,  94. 

Hyalite,  v.  Opal. 

Hydromagnesite,  94. 

Hydro-mica,  v.  Muscovite. 

Hydrozincite,  94. 

Hypersthene,  76. 

Iceland  spar,  v.  Calcite. 
Idocrase,  v.  Vesuvianite. 
Ilmenite,  v.  Menaccanite. 
Ilvaite,  96. 
lodynte,  90. 


I05 


lolite,  96. 
Iridosmine,  90. 
Iron,  36,  44. 
Iron  pyrites,  v.  Pyrite. 
Iron  stone,  v.  Siderite. 

Jade,  v.  Jadeite. 
Jadeite,  76,  86. 
Jamesonite,  42. 
Jasper,  84. 
Jefferisite,,  96. 

Kalinite,  62. 
Kaolin,  v.  Kaolinite. 
Kaolinite,  50,  56,  58,  64. 
Kermesite,  90. 

Labradorite,  78,  84. 
Lapis-lazuli,  v.  Lazurite. 
Laumontite,  64,  70,  78. 
Lazulite,  74,  82. 
Lazurite,  60,  74. 
Lepidolite,  66. 
Lepidomelane,  34,  60,  66. 
Leucite,  78,  84. 
Leucopyrite,  v.  Lollingite. 
Limonite,  28,  30,  36,  38,  50,  52,  56. 
Linarite,  94. 
Linnaeite,  44,  46,  48. 
Lollingite,  44,  46,  48. 

Magnesite,  68,  76. 

Magnetic  iron  ore,  v.  Magnetite. 

Magnetic  pyrites,  v.  Pyrrhotite. 

Magnetite,  36,  38,  44,  46. 

Malachite,  60. 

Manganite,  34,  36,  42,  44. 

Marcasite,  32,  44,  46. 

Margarite,  66,  72. 

Massicot,  92. 

Melaconite,  34,  42,  58. 

Melanterite,  94. 

Menaccanite,  36,  40,  54,  58. 

Mercury,  46. 

Mesolite,  96. 

Metacinnabarite,  90. 

Mica,  v.  Muscovite,  etc. 

Microcline,  96. 

Millerite,  30. 

Mimetite,  66. 

Mineral  Coal,  34   50,  58. 

Minium,  92. 

Mirabilite,  94. 


Mispickel,  v.  Arsenopyrite. 
Molybdenite,  32,  40. 
Monazite,  74. 
Montmorillonite,  64. 
Moonstone,  v.  Feldspar. 
Muscovite,  62,  66. 

Nagyagite,  90. 
Natrolite,  72. 
Nephelite,  78. 
Nephrite,  v.  Jadeite. 
Niccolite,  28. 

Obsidian,  84. 

Ocher,  v.  Limonite  and  hematite. 

Octahedrite,  92. 

Oligoclase,  84. 

Olivenite,  92. 

Olivine,  v.  Chrysolite. 

Onyx,  84. 

Opal,  64,  78,  84. 

Orpiuient,  30,  56. 

Orthite,  v.  Allanite. 

Orthoclase,  84. 

Ouvarovite,  v.  Garnet. 

Ozocerite,  96. 

Pearl-spar,  v.  Dolomite. 

Pectolite,  72. 

Pentlandite,  30. 

Petalite,  94. 

Petzite,  90. 

Phenacite,  96. 

Phlogopite,  26,  30,  62,  66. 

Finite,  70. 

Plagioclase,  v.  Feldspars. 

Platinum,  90. 

Plumbago,  v.  Graphite. 

Polianite,  44,  46. 

Polybasite,  90. 

Polycrase,  92. 

Polydymite,  42,  44. 

Prehnite,  86. 

Prochlorite,  60,  62. 

Proustite,  26,  50,  52. 

Psilomelane,  36,  40,  44,  46,  54,  58. 

Purple  copper,  v.  Bornite. 

Pyrargyrite,  26,  28,  32,  34,  50,  52. 

Pyrite,  32. 

Pyrolusite,  32,  40,  42. 

Pyromorphite,  66,  74. 

Pyrope,  v.  Garnet. 

Pyrophyllite,  64. 


T06 


Pyrrhotite,  28,  30,  32,  42,  44. 
Pyroxene,  60,  76,  86. 

Quartz,  54,  58,  80,  84,  88. 

Realgar,  26,  50. 

Red  copper  ore,  v.  Cuprite. 

Red  ocher,  26,  50. 

Rhodochrosite,  68,  74. 

Rhodonite,  74,  82,  86. 

Ripidolite,  v.  Clinochlore. 

Rock  salt,  v.  Halite. 

Rubellite,  v.  Tourmaline. 

Ruby  silver,  v.  Proustite  and  Pyrargyrite. 

Rutile,  28,  40,  54,  80,  82. 

Salt,  v.  Halite. 

Samarskite,  38,  52,  54,  58. 

Satin  spar,  62. 

Scapolite,  v.  Wernerite. 

Scheelite,  74. 

Scolecite,  96. 

Scorodite,  92. 

Selenite,  v.  Gypsum. 

Senarmontite,  92. 

Sepiolite,  64,  70. 

Serpentine,  62,  70,  72,  78. 

Seybertite,  72. 

Siderite,  50,  52,  56,  68,  74. 

Sillimanite,  80. 

Silver,  46,  48. 

Silver  glance,  v.  Argentite. 

Smaltite,  44,  46,  48. 

Smithsonite,  68,  74. 

Sodalite,  78. 

Spathic  iron,  v.  Siderite. 

Specular  iron,  v.  Hematite. 

Sperrylite,  46,  48. 

Sphene,  v.  Titanite. 

Sphalerite,  26,  28,  30,  34,  36,  50,  52,  56,  68, 

Spinel,  82,  88.  [  74. 

Spodumene,  84. 

Stannite,  90. 

Staurolite,  82,  88. 

Stephanite,  32,  34. 

Stibiconite,  92. 

Stibnite,  40,  42. 

Stilbite,  70,  72,  78. 

Stilpnomelane,  96. 

Stromeyerite,  90. 

Slrontianite,  68. 

Succinite,  64. 


Sulphur,  56,  62. 
Sussexite,  92. 
Sylvanite,  40. 
Sylvite,  90. 

Talc,  64. 

Tantalite,  38,  52,  54,  58. 

Tellurium,  90. 

Tephroite,  74. 

Tetradymite,  40. 

Tetrahedrite,  34,  42,  44. 

Thenardite,  94. 

Thomsonite,  72. 

Tiemannite,  90. 

Tin  stone,  v.  Cassiterite. 

Titanic  iron,  v.  Menaccanite. 

Titanite,  76. 

Topaz,  88. 

Torbernite,  92. 

Tourmaline,  80,  86,  88. 

Tremolite,  72,  80. 

Triphylite,  92. 

Triplite,  92. 

Tripolite,  64. 

Trona,  94. 

Turgite,  26,  28,  36,  38,  50,  52,  54. 

Turquois,  60,  78,  82. 

Ulexite,  62. 
Uraninite,  94. 

Valentinite,  92. 
Vanadinite,  56,  66. 
Vesuvianite,  80,  82,  86. 
Vivianite,  60. 

Wad,  32,  34,  50,  58. 
Wavellite,  70. 
Wernerite,  78,  84. 
Willemite,  74. 
W7itherite,  68. 
Wolframite,  38,  52,  58. 
Wollastonite,  72,  76. 
Wulfenite,  56,  66. 

Xenotime,  92. 

Zaratite,  94. 

Zincite,  26,  28,  30,  50,  52,  56. 

Zinkenite,  90. 

Zircon,  88. 

Zoisite,  80,  86. 


BOSTON     SOCIETY    OF    NATURAL     HISTORY. 

fteacbers'  Scbool  of  Science, 


MINERALOGICAL     AND     GEOLOGICAL 

SPECIMENS   AND   COLLECTIONS 

PREPARED  FOR  THE  USE  OF  TEACHERS  AND  STUDENTS. 

It  is  now  generally  recognized  by  the  best  teachers  that  satisfactory  results 
in  the  study  of  natural  science  can  only  be  obtained  by  the  liberal  use  of  speci- 
mens ;  and  unquestionably  the  difficulty  and  expense  of  obtaining  suitable  material 
has  been  a  great  obstacle  to  the  introduction  of  the  natural  or  scientific  method. 
The  vital  importance  of  this  matter  to  the  interests  of  sound  education  is  fully 
appreciated  by  Prof.  Alpheus  Hyatt,  of  the  Teachers'  School  of  Science ;  and 
with  his  aid  and  encouragement  the  collections  described  below  have  been  pre- 
pared for  the  express  purpose  of  supplying  schools,  teachers  and  students  with 
carefully  selected  educational  material  at  the  minimum  cost. 


ELEMENTARY  MINERALOGY. 

These    collections    are    designed   to   illustrate  Science  Guide  No.  xm.       ("First  Lessons  in 
Minerals,"  by  Ellen  H.  Richards). 

Collection  No.   I   includes  twenty  of  the  principal  elements  and  minerals,  of  which  it  is  im- 
portant to  have  one  specimen  for  each  pupil. 

I  large  specimen  of  each  kind,  20  in  all,  labelled,         .         $  .50. 
5  smaller  specimens  of  each  kind,   100  in  all,  .         .       i-25- 

Collection  No.   2  includes  ten  additional  varieties,  of  which  it  is  desirable  to  have  at  least 
one  specimen  for  every  two  or  three  pupils. 

I  large  specimen  of  each  kind,   10  in  all,  labelled,         .         $  .30. 
5  smaller  specimens  of  each  kind,  50  in  all,      .         .         .         .75. 


MINERALOGY. 

The    min'eralogical    collections   may    be  used   advantageously  with  Prof.  Dana's  Manual   of 
Mineralogy,  or  Text-book  of  Mineralogy,  or  any  standard  text-book. 
Scale  of  Hardness. — Price:  Cabinet  size,  $1.00;   Student  size,  50  cents. 
Luster  Series. — Six  specimens  illustrating  the  principal  kinds  of  luster. 

Price:  Cabinet  size,  $1.00. 
Cleavage  Series. — Ten  specimens  illustrating  the  principal  kinds  of  cleavage   in    the    different 

systems  of  crystallization.     Price:   Cabinet  size,  $1.50. 
Descriptive  Mineralogy  Series. — 

50  specimens.  100  specimens.  150  specimens. 

Cabinet  size,            .         .         .         .  $6.00  $15.00  $3°-°° 

Student  size 2.00  5.00  10.00 


DETERMINATIVE  MINERALOGY. 

The  scale  of  hardness  of  four  degrees  described  on  page  9  of  the  Tables  will  be  furnished 
for  25  cents;  and  the  list  of  fifty  minerals  on  page  21,  suitable  for  an  elementary  course  in 
determinative  mineralogy,  for  $1.50. 

Pure  minerals  suitable  for  blowpipe  analysis  and  chemical  experiments  are  sold  by  weight, 
the  prices  ranging  usually  from  5  cents  to  50  cents  per  pound. 


LITHOLOGY. 

The  lithological  collections  were  originally  prepared  to  illustrate  Science  Guide  No.  xn. 
(Common  Minerals  and  Rocks,  by  W.  O.  Crosby);  but  they  have  been  recently  considerably 
extended,  and  the  larger  ones,  especially,  may  be  advantageously  -used  in  connection  with  mure 
advanced  text-books. 

The  prices  of  these  collections  are  as  follows : 

50  spec's.         80  spec's.         125  spec's.         150  spec's. 

Cabinet  size  with  printed  labels,  .  $2.50  $4-5°  $9.00  $12.00 

Student  size,     .  .         .         .  -        1.25  2.50  5.00  6.25 

The  specimens  in  the  Student  collections  are  not  labelled,  but  are  numbered  to  correspond 
with  the  printed  catalogue. 


ECONOMIC  MINERALOGY  AND  LITHOLOGY. 

Many  teachers  desire  to  give  special  prominence  to  those  minerals  and  rocks  having  im- 
portant uses  in  the  arts.  To  meet  this  need,  the  following  collections  have  been  arranged : 

(i).  Ores. — This  collection  includes  30  typical  specimens  of  the  most  important  ores.  It 
embraces  ores  of  gold,  'silver,  mercury,  copper,  lead,  zinc,  tin,  iron,  etc.  Price :  Cabinet 
size,  $5.00. 

Economic  Minerals  other  than  Ores. — This  collection  includes  45  specimens  of  minerals 
having  important  uses  in  the  arts,  but  from  which  no  metal  is  obtained,  such  as  sulphur, 
graphite,  corundum,  gypsum,  apatite,  barite,  halite,  asbestus,  etc.  Price :  Cabinet  size,  $4.50. 
Collections  I  and  2  will  be  sold  together  for  $9.00. 


STRUCTURAL  GEOLOGY  OR  PETROLOGY. 

This  collection  consists  of  30  specimens  illustrating  nearly  all  the  most  important  kinds  of 
structures  occurring  in  rocks,  as  follows:  Stratification,  Ripple-marks,  Rain-prints,  Mud-cracks, 
Fossils,  Veins,  Dikes,  Stalactites,  Joints,  Cleavage,  Faults,  Folds  and  Contortions,  Concretions, 
Glacial  Striae,  etc.  Price :  Cabinet  size,  $8.00. 


HISTORICAL  GEOLOGY. 

Stratigraphic  Collection. — This  includes  100  specimens  of  the  characteristic  rocks  of  the 
various  geological  formations  from  the  Laurentian  to  the  Tertiary.  Price:  Cabinet  size,  $8.00. 

Paleontological  Collection. — This  embraces  50  species  (about  100  specimens)  of  fossils, 
selected  from  the  characteristic  forms  of  the  different  formations.  Prke:  Cabinet  size,  $8.00. 


APPARATUS. 

The  Apparatus  required  in  using  these  determinative  Tables  will  be  furnished  as  follows :  — 
Brass  Blowpipe,  .20;  Alcohol  lamp,  .25,  Bunsen  burner,  .45;  Steel  forceps,  .10;  Platinum  wire, 
.15;  Glass  tubes,  open,  .10  per  dozen;  closed,  .15  per  dozen;  Hammer,  anvil  and  ring,  .30; 
File,  .10;  Magnet,  .15;  Lens,  .80;  Test  tubes,  .05  each;  Streak  stones,  .25;  Litmus  paper,  .10. 

All  orders  should  be  addressed  to 

GEO.  B.  FRAZAR, 

West  Medford, 

Mass. 


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